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Jorge Pullin: mark.

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Jorge Pullin: Sebastian Stein House will speak about course greening.

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Sebastian Steinhaus: yeah Thank you haga and very grateful for this opportunity to talk again in the ids.

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Sebastian Steinhaus: I actually realized that it has been five years since I last gave a seminar of asking for talking this in the series and back then was still while landline phone and remember having lots of technical difficulties so we've actually come a long way and.

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Sebastian Steinhaus: Today, the topic is so as the title says cause gaining organizations been firms and most of what i'm going to talk about you can find that this review that I wrote last year.

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Sebastian Steinhaus: But many of these aspects that I will talk about will not be super technical, but you know, please interrupt me at some point, if you have any questions.

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Sebastian Steinhaus: And just to kick things off I think we're all familiar with realization as a universal universal to physics, to actually relate dynamics at different scales and.

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Sebastian Steinhaus: So the general idea is that, for example, if you have a theory that lives at very short length skills.

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Sebastian Steinhaus: You can integrate our two piece of freedom to arrive at an effectively at larger scales, so in that sense, you can try and zoom out and relate series that are defined at different scales and.

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Sebastian Steinhaus: If we are doing quantum gravity and particularly quantum gravity forms.

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Sebastian Steinhaus: are bottom approaches, so we propose new physics at ultraviolet scales, so to speak, and then you have to make sure, first of all, we have to make contact again with the observable world on large scales.

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Sebastian Steinhaus: But also we have to make sure, actually, that the ceiling is like the UV completion of relativity and then it actually is, you know physics at these short scales.

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Sebastian Steinhaus: So naturally you might think that innovation is the right tool to do that, but.

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Sebastian Steinhaus: As I mentioned before, usually you talk in terms of length scales, and if you are in the background and inserting you do not have a scale, so how can you define when was he in the setting, first of all, and.

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Sebastian Steinhaus: Second question is, how can I potentially help us address computation and challenges and one of these images that comes up very often is, for example, minimization escapes theory so.

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Sebastian Steinhaus: For example, let's gives you is like the one of the typical places where length scale comes in, because you describe your space time you have a letter scale a unit and steering basically you ignore any physic that is below that scale, so you could argue that this theory has a Ryan has.

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Sebastian Steinhaus: or isn't effectively, so to speak, by integrating more degrees of freedom, but it is also a setup to do to perform on the target of calculations so, for example, if you have an observable or let's say Wilson loop.

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Sebastian Steinhaus: That you, for example, that i've tried to draw here in two different settings so one would be that you have a large scale, a and the provenance get a prime.

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Sebastian Steinhaus: And both of these theories like should be perfectly fine to give me a good expectation that you have this observable because both legacies are, so to speak, fine enough.

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Sebastian Steinhaus: to represent this, but the question is, do these results actually agree.

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Sebastian Steinhaus: When, what do you usually must do is that you have to tune your theory, according to the letter scale at which you're probing physics, so this could be, for example, the set of coupling Constance.

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Sebastian Steinhaus: Now let us get to the readers actually rather not necessarily straightforward to do, but you have a lot of information at your disposal, we have experiments.

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Sebastian Steinhaus: And you have a realizable quantum field theory in the continuum that helps in this endeavor So the question is, how does this.

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Sebastian Steinhaus: Set up actually translate to the backup independent setting and what is the interpretation of such organization would flow, or like how one relates series at different scales so.

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Sebastian Steinhaus: And this is like the idea that want to get across today in the stock so first of all I want to briefly talk about spin for models in a nutshell.

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Sebastian Steinhaus: Very non technical brief, then I want to explain the principles behind back and realization that gives you two numerical examples, how we.

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Sebastian Steinhaus: tackle this in the past, one is natural minimization the other one is exploring so restricted same classical four dimensional spin for models.

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Sebastian Steinhaus: Where I will also take like a few new developments which are not strictly related to cross training and then I give you a brief summary and outlook.

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Sebastian Steinhaus: So, to start with, like the elevator pitch or spin from gravity so spin firms attempts to define quantity of gravity as a pathological of geometries and, as you know, from Mexico classical powerful integral.

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Sebastian Steinhaus: If you want to define blackness the sum of all possible path.

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Sebastian Steinhaus: What you usually to do is introduce in regulator, so, in our case would be discrimination, a too complex to set your fire, how many degrees of freedom we make this possible, but defined.

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Sebastian Steinhaus: Now the degrees of freedom it's been phones are quantum geometric building blocks, they are derived from constraint about.

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Sebastian Steinhaus: quantum field theory which on Shell is a permanent to general activity and we have a discrete areas spectrum.

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Sebastian Steinhaus: And the physical economy of the theory our transition amateurs so to each geometry that we have is an amplitude, which is supposed to be proportional to the exponential of items as an open action.

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Sebastian Steinhaus: And we have very good agreement with this at least one single building block we find we that we recover discrete gravity so called J limit in sockets in the classical.

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Sebastian Steinhaus: And most importantly, we have wanting attitudes they're not be rotated and the spin from models, the employment, make a reference to back on geometry, and we aim to implement different often symmetry in these models.

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Sebastian Steinhaus: And a bit more detail this regulator is usually dual too complex, so we make an assignment of vertices.

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Sebastian Steinhaus: edges and faces for this too complex and we call it with group theoretic data isn't back representations irreducibly representations of the symmetry group underlying theory and in very intensive the intertwining of the 10s of product of these images with presentations.

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Sebastian Steinhaus: On the boundary we have a graph and they are this data and uses a three dimensional geometry, so the entertainers our tool to play the drum.

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Sebastian Steinhaus: And the representations improve the areas of the faces of these policies and then, when evolve this geometry we get what we wanted by a four dimensional by john tree.

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Sebastian Steinhaus: and basically obtained from sample one history that interpolate between these two boundaries.

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Sebastian Steinhaus: And then to obtain for pathological is some of all these histories, so all intertwines after presentations and.

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Sebastian Steinhaus: All of that and these emulators will play a key role during the store, which I will just call an amateur functional in the sense that.

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Sebastian Steinhaus: They map states from the boundary who have a space for the complex numbers and in the example here we have an initial hilbert space finite the final hole but space, so the 10s of product is Texas terms of product with little bit spaces and then.

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Sebastian Steinhaus: The amplitude gives us the condition amplitude of why this part of the transition aptitude between these two States sometimes also called the physical in our product.

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Sebastian Steinhaus: And overall be vital to petition function of these models by locally assigning amplitude so we have for the phase we have for the edges.

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Sebastian Steinhaus: And then the keyboard, which is the vertex amplitude, which is the contraction here here for the force and FLEX a contraction of five.

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Sebastian Steinhaus: tetrahedron where each of the tetrahedron or corner geometric building blocks in the sense that if you give given by the data, the geometry is not completely specified, so in that regard supermodels scribe quantum space time as a superposition of corner geometric building blocks.

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Sebastian Steinhaus: And this is still one of these presentations and it's like so very appealing to me about spin for models, but we shouldn't forget that there are so many questions that we need to tackle.

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Sebastian Steinhaus: And this, and I think that many of these questions can actually be addressed via remember ization by across grading.

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Sebastian Steinhaus: And, for example, there are exist ambiguity in the definition of the fourth dimension models and, as I mentioned before this there's no.

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Sebastian Steinhaus: guiding principle in theory that that tells you which too complex, you should choose.

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Sebastian Steinhaus: So it doesn't tell you, but you should pick a very cost too complex, whether you should take a very fine one.

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Sebastian Steinhaus: And so generally your your predictions will depend on this choice, so there are two ways hours, so you could say that you want some or two complexes or that you want to refine.

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Sebastian Steinhaus: refine it was raining and I will talk mostly today about the second part, but I will comment on these two choices on the next slide.

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Sebastian Steinhaus: And the question what happens too often symmetry which is generic departments, how can we restore if it wasn't symmetry, but if you, for example, interpret this as a regulator, we must make sure that physics must be independent of the choice of the regulator.

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Sebastian Steinhaus: And the second part is and other computation challenges, so one is, for example, the computation of the words attitude another one is something over configurations and another one would be, how can we actually computer circles.

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Sebastian Steinhaus: Whether they do have observed was a notice, of course, then the different story, but let's just say that wants to learn how certain things behave from these models.

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Sebastian Steinhaus: And in the recent few months or like they say the recent yet in recent years, there has been very encouraging progress along these three fronts.

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Sebastian Steinhaus: For the violence and iTunes several people in my SA P told on someone's personality josh is on others and be able to give her to talk by Francesco pazzini.

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Sebastian Steinhaus: about this in the series deal, for example with computing the verdict amplitude insurance in detail of a model and then set assented bianca discretion haggard have pushed very much I have explored the super effective spent four models.

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Sebastian Steinhaus: with which they can actually own study larger translations and some over these.

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Sebastian Steinhaus: were lots of configurations, and I think at the end of last year.

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Sebastian Steinhaus: So people around machine Han have started exploring computing observers using left, vegetables and using Markov chain watercolor techniques.

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Sebastian Steinhaus: So these are all very encouraging encouraging lots of encouraging progress which, I think, in the end also help towards understanding position but coming back to this choice whether to some or whether to call screen or whether refining.

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Sebastian Steinhaus: And I think these are two complimentary roads to addressing the same.

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Sebastian Steinhaus: Addressing the same questions, basically, how can we make sure that predictions of one model do not depend on the ambiguity Stephen and, for me, if you want to some over to complexes the.

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Sebastian Steinhaus: The technical tool to formulate this consistently is confused theory, in which you some of all triangulation and apologies and you treat the model as a quantum field theory.

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Sebastian Steinhaus: So in it's been fun attitudes and appears fame and diagrams and you have a very different interpretation name is that you're building blocks actually become atoms of space time.

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Sebastian Steinhaus: And he, of course, if you treat as a confused theory, the question is as consistent as a chronic fatigue, which means is that we normalize bubble as a non pejorative on a theory.

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Sebastian Steinhaus: And the opposite perspective is like whether I want to explain today's the refining cross training, one where we want to perform revelations for fixed regulations and treat.

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Sebastian Steinhaus: The too complex itself as a regulator so then we basically have to address the question.

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Sebastian Steinhaus: What is the impact of US regulators, so can we relate theories that are you finding different regulators and how can we move the regulator, in the end in a non trivial continuum slash refinement limit.

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Sebastian Steinhaus: And I would say, well, I want to emphasize that these rounds are complimentary because questions that are easy to address and one of them are very difficult for the other so.

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Sebastian Steinhaus: In group, in theory, the point of discussing the policy change comes around much more, naturally, whereas, for example in the refining constraining one, we have a lot of control, about the setting because we can just work on a fixed trying to make sure.

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Sebastian Steinhaus: But this completes know the first part of my talk now go to the second part, but backward independent minimization and are there any questions up to this point.

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Abhay Vasant Ashtekar: It can I just ask one general question.

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Sebastian Steinhaus: The basically the point.

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Abhay Vasant Ashtekar: You know the point up here is that, in order to kind of filter is it a background space time, and so there is a control on how you define me refining or which parts to include I mean there are.

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Abhay Vasant Ashtekar: Exactly soluble models nonlinear theories, in which people sort of do that they put an alternate cut off infrared cut off with them and some.

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Abhay Vasant Ashtekar: People like fried fish always were concerned about our programs because they said, well, there are many, many refinements you could do to get the continuum debate, I mean you.

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Sebastian Steinhaus: hinted at apologies.

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Abhay Vasant Ashtekar: But your diagrams are all piece by piece wise linear categories, I could use some other category.

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Abhay Vasant Ashtekar: And so what and therefore there is another whole bunch of ambiguity is, which is not even written here when you said that physics should be independent of that.

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Abhay Vasant Ashtekar: and probably just basically saying is completely hopeless to control all those things, and so this program doesn't even our hope now I have my answer to that which I can give you a minute, if you like, but I just wanted to know what you do point you would be about this.

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Sebastian Steinhaus: Well it's.

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Sebastian Steinhaus: I mean, as far as I understand, for example, lettuce Casey you mostly discussing.

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Sebastian Steinhaus: For example, you know flat space times and then regular dispositions and I think that was best under control, I don't know whether people are doing random letters, these are what they are doing makino oh let's get through in code space is also very difficult.

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Sebastian Steinhaus: I would say for the time being.

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Sebastian Steinhaus: I mean we've officially request to be aware of these issues, but first trying to see whether we can make things work on auto if something goes wrong, I mean, I have a rather pragmatic point of view and.

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Sebastian Steinhaus: What first of all try to.

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Sebastian Steinhaus: test some of these ideas in a controlled setting so in my case is good, for example, the for the time being, not due to for to change, for example, and i'm just.

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Abhay Vasant Ashtekar: Otherwise, things can become uncomfortably.

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Abhay Vasant Ashtekar: So my point of view, they basically the same first part of is the same as yours, but I would like to take you on a stronger point of view that we already defined the theory.

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Abhay Vasant Ashtekar: And so you know we perform a particular democratization and particular piece by the media and the I get it.

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Abhay Vasant Ashtekar: Now, if we actually were to, and that is our definition of the theory now if one gets some other democratization, for example, piece wise analytic but arbitrary not leaving at all.

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Abhay Vasant Ashtekar: and actually were to get another answer, well then that's another theory right, I mean and then one would worry about is the same as what you're saying, but I kind of feel that it is enough to give you.

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Abhay Vasant Ashtekar: A very defined definition here i'm saying this because this this this problem comes up when you talk to rigorous quantum field theory is very, very often.

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Abhay Vasant Ashtekar: And so I think, just so that everybody in the community knows that this is not some you know federal obstruction we just say that that defines theory and that's what we will analyze and.

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Sebastian Steinhaus: is exactly and and i'm so so, for example, take the cases that i've studied so far, you would rather call for example, like total orders of certain, for example.

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Sebastian Steinhaus: boundary states to investigate these questions, because this is something that you can do you have you know regular metrics.

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Sebastian Steinhaus: and have everything much more control, and of course you can ask the question shouldn't you consider these things and other parts as well.

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Sebastian Steinhaus: Of course you can always do that, and you probably should, but I think first of all, one can want to try and see whether what we've defined so far actually can make sense and what you can expect something out of it.

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yeah.

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Sebastian Steinhaus: OK so maybe I just start explaining them to better independent.

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Sebastian Steinhaus: So, as I said before.

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Sebastian Steinhaus: it's been formulated in terms of.

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Abhay Vasant Ashtekar: Absolute functions, like you, you have to.

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Sebastian Steinhaus: Remember to that map service states in the hood space to the complex numbers and cross training generically involves two main steps on the one hand, you have a something of a final piece of freedom.

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Sebastian Steinhaus: For example, that I tried to draw here, so this is of course a very simplified image spend from Santa two dimensional and the variables, of course, more intricate but it's as simple as the time being, just to explain the principles.

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Sebastian Steinhaus: So what you basically do in class when is that you, for example, to a certain kind of blocking to say that I want to combine these four attitudes now into one effective one.

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Sebastian Steinhaus: By summing over these five degrees of freedom here deteriorate, the defined some you know, a new attitude which lives on a different space.

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Sebastian Steinhaus: And to relate back to the original one I need to define so called embedding maps so that essentially these maps Tommy information, how to activate freedom for example under refining so to go from the core state to find state.

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Sebastian Steinhaus: The embedding PepsiCo this information and.

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Sebastian Steinhaus: If basically defined from the new effective So what is the and I will explain what this means so embedding the absence of course nothing new.

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Sebastian Steinhaus: For people who look on gravity i've explained us later on and but the idea is that we have different herbal spaces so different boundary date or different boundaries can.

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Sebastian Steinhaus: Carry different numbers of degrees of freedom, so to speak, and does carry different spaces and we want to identify no software defined.

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Sebastian Steinhaus: equivalents of States across spaces so and the idea is that we want to represent the same transition, so the same transition from the tools for example different as good as Asians.

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Sebastian Steinhaus: And that way we can wait by embedding maps, we can define partially or a sense of boundaries and thus public spaces, for example, if you have stayed.

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Sebastian Steinhaus: In one of open space in the state another where I can embed be in to be trying, I can compare both States by.

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Sebastian Steinhaus: Looking at the embedding of state five be compared to filebeat prime so I find those states which live in different spaces to be equivalent if they agree on the sample space and with this construction, you can define an affiliate space.

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Sebastian Steinhaus: And the key point is of course the consistency of these embedding maps, so it shouldn't matter if you have a this you know these.

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Sebastian Steinhaus: sections of bound or these these refinements of boundaries it shouldn't matter web which deleted boundary and digest states, and you can compare states that live in different spaces by embedding them into a corner.

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Sebastian Steinhaus: And these are decent batting gloves on nothing new, we knew it from from some for the Stephen m Ross deduction for the network states where.

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Sebastian Steinhaus: We can add links nodes in the in the network, but to say that these new links can be representations zero and the BF vacuum, there was recently developed by a few years ago by the invitation to market.

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Sebastian Steinhaus: is one which is based on having a flat connection so now, but these embedding maps are kinematics embedding maps and now the difficulty in cross training is, if you want to define the chemical embedding so that are consistent with the dynamics that is included in the sprint from aptitudes.

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Sebastian Steinhaus: And if we have these embedding NAPs this defines for us realization group equations for our spin from competitors, so to speak, so I have my attitude, a prime ab primary rather say.

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Sebastian Steinhaus: and combining it with the embedding map defined something and effective amplitude on the original space and on the level of a petition function, I start, for example, with the original ones with the original data.

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Sebastian Steinhaus: And, basically, I use this embedding episode speak to disentangle these.

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Sebastian Steinhaus: normalized attitudes from the others and define new effective attitudes and the important part is that you can see here is if I define the new effective constitutes is defined by something over all.

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Sebastian Steinhaus: All you know data or find data in between.

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Sebastian Steinhaus: So this is a very different concept, because there's no restriction on what these data sharing code, so these could be, for example.

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Sebastian Steinhaus: Smaller geometries this could be not geometries.

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Sebastian Steinhaus: Important here, so this is very different than in some sense under minimization there's something of all kinds of skills already, and this in the interpretation of this this comes up again so.

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Sebastian Steinhaus: What is what does this actually mean so we define a realization good flow of aptitudes so we go from initial attitudes to normalized points and that's defined them across several to complexes.

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Sebastian Steinhaus: via the slope attitudes, we can uncover the face diagram of the theory, for example, by identifying tractor fixed points and dust university trance states.

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Sebastian Steinhaus: And, as I argued before these realization will be creations must hold in principle for all kinds of laundry states right so it's impossible for a boundary states, this should hold also for all scales, because the scales is included in the boundary state.

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Sebastian Steinhaus: This is of course a high end i'm sure your condition and that's knowing the entire realization flow.

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Sebastian Steinhaus: including this condition actually means that you must solve the dynamics and.

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Sebastian Steinhaus: Moreover, if if you want to remove the regulator and obtain a theory that has propagating degrees of freedom, you must search for a fixed point and a second order face.

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Sebastian Steinhaus: Now, of course, as I just said, solving the theory, in the sense to all scales is higher non trivial and probably not possible right in general relativity we do not know all possible solutions to theory.

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Sebastian Steinhaus: And so, this is this seems a bit unrealistic, but what we should at least be able to do is do this numerically.

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Sebastian Steinhaus: or at least not just America but also approximately right so in a sense, these this cosmetic procedure is also a prescription for efficient and.

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Sebastian Steinhaus: Calculations so instead of evaluating the whole partition function at once you evaluated in parts.

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Sebastian Steinhaus: Right and I could say example since then say if I have a very finite as I use the empty and never ever ever COs lettuce I can perform the same calculation using the normalized me to a price.

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Sebastian Steinhaus: But approximation interpretations unnecessary and essentially you can study the cause of deliverables on the courses conversation with your effective theory and I will explain how this can be done in practice wire consumption minimization.

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Sebastian Steinhaus: Are there any questions yeah.

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Abhay Vasant Ashtekar: Can you just say what skills means because we, as we emphasize.

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Abhay Vasant Ashtekar: On independent, and so we don't know.

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Sebastian Steinhaus: Yes, scales In this sense, I mean the relative scale given by the lettuce or by the by the too complex, so I can always say that if I have to to come to competencies.

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Sebastian Steinhaus: I can differentiate them having a concept of final, so the final would be at a shorter relative scale compared to the cost of one so in a sense, you replacing short skills and knowledge, skills, by finance course, so to speak.

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Abhay Vasant Ashtekar: or for the body states, you could just say that it is more and more refined or.

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Abhay Vasant Ashtekar: Exactly major areas associated the volume subtitle or.

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Abhay Vasant Ashtekar: Is that.

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Abhay Vasant Ashtekar: Is that OK, with you or not, because here you are talking on hold for all Bombay.

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Sebastian Steinhaus: Yes, so it's.

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Sebastian Steinhaus: Yes, precisely right, so this must hold if I am basically represent the same kind of boundary geometry.

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Sebastian Steinhaus: And i'm different dispensations.

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Sebastian Steinhaus: If I can do this, then this should hold.

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Sebastian Steinhaus: and dozens of course hiding and trivia because the boundary geometry, you can be very small, it can be very large.

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Sebastian Steinhaus: So that's the Nice part about this.

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Abhay Vasant Ashtekar: But, but in the last remark you're talking about the States, but in the.

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Abhay Vasant Ashtekar: Earlier, women are also the refinement in the in the buck, so I think you're the boss.

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Sebastian Steinhaus: Yes, but it's formulated with respect to the boundary States actually.

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Abhay Vasant Ashtekar: Right yeah.

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Sebastian Steinhaus: Okay, so let me come to the part about transmission minimization to maybe explain a bit more hostile system practice.

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Sebastian Steinhaus: And many of the things that you see now seem to be very familiar, because the drawings that previous previously did will look very similar to what happens here.

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Sebastian Steinhaus: So intense national organization, do you ride your petition function as a test network, so what was previously before now becomes a cancer and the tensor is.

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Sebastian Steinhaus: there's nothing fancy about it just means that you have a certain you have your legs, and these are the legs of the tensor.

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Sebastian Steinhaus: carry the data of the theory essentially so basically your boundary states on called it out, it just as indices in this tensor.

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Sebastian Steinhaus: And the tension of practice means that if you have connected edges you or something over these data so.

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Sebastian Steinhaus: Basically, the partition function is here expressed as a as a contraction of this cancer network and a tensor also just if you look at if you're thinking about a computer it's just a much dimensional array.

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Sebastian Steinhaus: and intense realizations perform local manipulations of networks, so you have something over five degrees of freedom and then define the numerical variable transformations and from patients.

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Sebastian Steinhaus: And it isn't right algorithm so he directed some of the configurations and use a single evaluated composition, to define these value very good transformations.

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Sebastian Steinhaus: And the key idea is that you want to approximate the same partition function, for example, that is included in this in this financing network on the cost one.

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Sebastian Steinhaus: And it doesn't make any reference to background background structure background scale and it gives you a realization flow of local activities, and this is what I want to emphasize these from a local, in the sense that the tenses only talk with a direct neighbors.

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Sebastian Steinhaus: And these these two steps or the things about your composition.

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Sebastian Steinhaus: Basically happens as follows a day it has many very many, many variants of this algorithm but one example is just a following so, for example, you take for these tenses and you some of these internal degrees of freedom and you get a new tensor which now just carries more lex.

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Sebastian Steinhaus: Now what you can do is huge can from the sensor define a matrix that basically has these two indices as one index, and the other one is the other.

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Sebastian Steinhaus: The other index of the matrix and you can perform than a single device composition so just a simple linear algebra operation, what happens is you basically split your attention to, so there are 3,000,000,001 and then higher than one here this idea notes the single value.

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Sebastian Steinhaus: Which are ordered in size so it's like a.

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Sebastian Steinhaus: it's like a diamond ization of matrix or just more generalized and the important part is that these green maps here are actually unitary maps and these define a variable transformations you from the five degrees of freedom to effective consequence of freedoms.

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Jerzy Lewandowski: What does it mean dynamical.

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Sebastian Steinhaus: The medical in the sense, because you are deriving from the 10s and 10s of contains.

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Sebastian Steinhaus: medical information so, for example, it could be anything either today or in the using model, it could be you the weights that you assigned to the edges, so you compute this in the sense from the dynamics of the aptitude.

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Sebastian Steinhaus: Does that answer your question.

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Jerzy Lewandowski: and

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i'm not sure.

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Jerzy Lewandowski: If we can see that brown super model.

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Jerzy Lewandowski: in which the graphs represent actually dynamic actually dynamical states dynamical degrees of freedom so so as opposed to.

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Jerzy Lewandowski: quantum gravity vacuum quantum gravity so, then what happens.

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Sebastian Steinhaus: i'm honestly not sure how this how this translates to the setting exists.

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Sebastian Steinhaus: yeah so yeah maybe just to explain it again here it's it's just i'm just defining redefinition of so it's a single vertical position is a is nothing more than a very good transformation of these models, but it's derived according to the relevant so.

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Sebastian Steinhaus: As an example from the easing model, for example, where when applies these typically.

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Sebastian Steinhaus: When often uses 10 snippets as like a test example.

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Sebastian Steinhaus: Right these various transformations depends, for example, on your initial coupling constant very much so, depending on this.

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Sebastian Steinhaus: Very good transformations with great difficulty and that regard how you add or remove degrees of freedom depends on this, in that sense it's unethical.

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Sebastian Steinhaus: OK so maybe I just.

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Sebastian Steinhaus: continue.

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Sebastian Steinhaus: On so, for example, and this, as I said before, the screen parts to present unitary maps right and if I basically effect contain or if I combine this one, with its.

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Sebastian Steinhaus: mission control, but like here and I some over these single values and between a big cover basically my two lines, but because of these.

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Sebastian Steinhaus: The size of the similar values I can actually truncate the song so usually like these indices half an hour is called often upon dimension of kind.

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Sebastian Steinhaus: The combined one, of course, once over opens up this Chi Square and if I wanted to run America simulations eventually run out of memory, so I have to truncate the song but.

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Sebastian Steinhaus: I can, if the singer values behave in a nice way I can repeat in such a way that I basically can approximate on the right hand side very well by something which has drastically so freedom and.

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Sebastian Steinhaus: After including this and competing I can define new effective transfer so basically between each pair of these sort of like.

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Sebastian Steinhaus: New tenses with my legs I include these resolutions of the identity or truncated resolution to the identity and define and obtain effective tenses.

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Sebastian Steinhaus: And just some to to flash on properties on of these terms networks, they actually very efficient for us like aptitudes so.

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Sebastian Steinhaus: There, because he has some directly over five degrees of freedom you're not you're not i'm.

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Sebastian Steinhaus: Saying sampling over them seo and Monte Carlo simulations.

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Sebastian Steinhaus: It works very well for for oscillating attitudes and they also very opposite to Monte Carlo simulations because you do not consider the entire system at once, but rather a.

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Sebastian Steinhaus: Just everything at a very local level and just evaluate things in steps.

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Sebastian Steinhaus: And you can know what the face diagram so it's just I mean I kind of explain where this is coming from one of our papers but.

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Sebastian Steinhaus: Essentially, each color in the face diagram denotes a different attractive final fixed point of this minimization workflow.

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Sebastian Steinhaus: So you can map out the face diagram via the attractive fixed points so you just let your you start with a particular choice of initial parameters and you let the system flow and that determines for you the face and often also to face.

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Sebastian Steinhaus: And that every find the phases phase transitions and it's also very good actually to see whether, for example, these places are have first of first or higher order, because if they are, for example, of second or you expect.

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Sebastian Steinhaus: Almost scaling variants yet this face musician so by that I mean that the system remains very long closer this fixed point.

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Sebastian Steinhaus: that's okay it on this other space, in addition, but also deserts have disadvantages, so they require final dimensional spaces, because you're performing jabra for Asians.

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Sebastian Steinhaus: So everything must fit into the memory of your computer on your supercomputers and the new mega costs grover's complexity and this complexity can be, for example.

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Sebastian Steinhaus: Symmetry group, it can also It can also, of course, be the dimension of your system, because if you have higher dimension systems.

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Sebastian Steinhaus: Please encourage you need more data to encode states in these higher dimensions systems.

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Sebastian Steinhaus: And that is one of the obstacles that makes it very difficult for next netflix actually to go beyond two dimensions.

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Sebastian Steinhaus: And in previous work we've started, for example, to dimension and a lot models for quantum groups.

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Sebastian Steinhaus: And also defines or decorated terms networks for three dimensional landscape, the risks and the left hand side is, for example.

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Sebastian Steinhaus: decorators and metrics that carry spin network states and this brings me now to the next part of the top where.

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Sebastian Steinhaus: One difficulty for specific States is that they are unfortunately not stable and the cost grain, which brings me to like one of the important works from last year, which is super decorated tense networks with fusion charges.

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Sebastian Steinhaus: So, of course, this case studies, but also spent from was because they are very much formulated in a similar spirit of know writing gravity as a gateway theory.

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Sebastian Steinhaus: Let us get through is actually a challenge for 10s networks, because you to the gauge cemetery you have a certain redundancy in zero degrees of freedom.

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Sebastian Steinhaus: And you're very good I have local science, so what you actually need is an efficient representational responder data and you wants to avoid these redundant gatekeepers of freedom and.

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Sebastian Steinhaus: You want it to be stable on the cross training and then three dimensions younger did question mark uh yeah defined the so called fusion basis, at least for the quantum group and then came.

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Sebastian Steinhaus: To come with bianca description of the other define it for.

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Sebastian Steinhaus: I think, at least for finite groups might be and find groups, the so called fusion basis and the point is that you are constructing your space must emphasize again, it is in three dimensions.

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Sebastian Steinhaus: By having by looking at a two sphere with certain amount of punches so, for example, here in the States to you for a cube you have basically one puncher for each of the phases.

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Sebastian Steinhaus: And these punches can carry magnetic and electric citations of unit escapes theory in gravity with quantum curvature and.

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Sebastian Steinhaus: torsion degrees of freedom So these are essentially like like point particles carrying a muscle spin so basically everywhere, when there is no puncture the systems flat and closed loop that do not contain any of these functions can be contracted.

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Sebastian Steinhaus: But these mentees punctures are carrying the only possible expectations and this the clue of this fusion basis is in order to define it, you must define a so called fusion tree now, what is the great part about this fusion tree.

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Sebastian Steinhaus: Basically, the choice of order in which you glue of fuse these functions together that makes what makes a certain choice of critical servers.

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Sebastian Steinhaus: So, essentially, if you want to measure an observer, for example, of loosened up around to punctures and he only needs to across this huge tree once this operator is actually bag minimized by this.

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Sebastian Steinhaus: Fusion bases so, for example, the punctures wanted to I can surround them directly and.

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Sebastian Steinhaus: Diverse loop around these two punches will be directed Nice.

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Sebastian Steinhaus: On the other hand, for example, if I want to measure here around three and four, this is not possible, but I can choose a different fusion tree, so I can perform a.

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Sebastian Steinhaus: basis transformation to a different fusion prefer one to measure that up so so this fusion tree contains information about the set of communications.

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Sebastian Steinhaus: How does this help us for cross training so.

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Sebastian Steinhaus: The idea is that example under course grading and I have my states that are assigned to to these cubes eventually I want to stick to the script to cubes together, and I would like them to define effective punctures.

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Sebastian Steinhaus: That then coach effective degrees of freedom for this cause face.

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Sebastian Steinhaus: Now, if I do this get, for example, this big fusion tree here for 10 punches that corresponds to this guy on the right hand side.

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Sebastian Steinhaus: But what I want to do is, for example here for the screen face and for the red face, I would like to define an effective puncture.

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Sebastian Steinhaus: For this, that it goes basically just the data that I need for this cause face, so what it does need to do is I take my original state and transform the fusion basis.

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Sebastian Steinhaus: To a tree that they internalize these two aptitudes So these are actually many transformations and I don't have time to show them here, but I go basically from this state, because the state which now.

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Sebastian Steinhaus: They have analyzes these on these two states which I can then use as effective punches that Why can I do this so, for example, the observers, which are, for example, words and groups.

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Sebastian Steinhaus: actually do not depend on the individual labels here for two and two prime but they only depend on this label here and I will use this I use this them to define an effective function effective label and compute concepts which brings me back to the first idea that I presented today.

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Sebastian Steinhaus: Namely.

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Sebastian Steinhaus: For example of what I could do is just stick, many of these of these cubes together and then, for example, the observable runs these four buckets.

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Sebastian Steinhaus: And you can say, well, you just choose a infusion tree that merges these four punches together and go through the effective label, for example, Jay Jay primer which then driven operated.

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Sebastian Steinhaus: As they analyzed, which is something which is numerically incredibly difficult to do so, what we do instead is the first course grain.

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Sebastian Steinhaus: and basically get an effective and the truth, but just that just has, for example, this effective functionalities labels on this course face, and then I measured the.

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Sebastian Steinhaus: expectation value of my ribbon operator on this course label, you know, on the right hand side, and this, for example, what we did in the paper that I wrote, together with William Cunningham and the last year, the birth of fusion basis for quantum theory and so.

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Sebastian Steinhaus: As you know, the three dimensional on a group.

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Sebastian Steinhaus: has an uppercut of on the.

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Sebastian Steinhaus: On the representation labels, so this leads to or that way, we are dealing with this final dimension hookah spaces, but what we find is at finite K.

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Sebastian Steinhaus: We see two phases, we see a confining face so a strong coupling phase in a deeper and finding week copying face legislature.

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Sebastian Steinhaus: And the interesting part is, as we increase the level K So these are just two different models, but the behaviors the same.

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Sebastian Steinhaus: We see that this this critical coupling at which this is facing position across actually decreases which seems to indicate that if we go back to the usual, as usual, so we sent a K to infinity.

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Sebastian Steinhaus: And this is critical coupling might go to zero, so that way, only the confining Facebook, so it turns out that the be confined to the public, face actually vanishes for continues as YouTube.

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Sebastian Steinhaus: And the other part, is we actually measured the expectation value of wisdom looks at the setting, so this is, for example, the Wilson group in.

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Sebastian Steinhaus: The strong coupling setting and i've drawn it here over the areas squared of the cross pockets and we see like this Nice in your behavior which is typical for the area law in the strong coupling proceed.

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Sebastian Steinhaus: and

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Sebastian Steinhaus: Because make this this.

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Sebastian Steinhaus: is actually very costly, so I want to use it later on to other projects, for example in three dimension that escape the reed and bianca we thinking about a cosmological constant model three dimensions, where you can think about taking, for example, the.

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Sebastian Steinhaus: vacuum for a customer to constant that is larger and embedded into the system or like.

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Sebastian Steinhaus: What should be the same for me, so we can take the system, for example, with the smaller K and embedded into a system with a larger cadence would correspond of.

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Sebastian Steinhaus: embedding, for example, system from a larger project once cosmetic issue system to the smaller one, and the question would be, for example, can we see something like.

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Sebastian Steinhaus: condensation of curvature defects into a new, effective action within, for example, larger theory analogous to an organization and the question is whether we can do further optimizations, for example, one building blocks employing matrix multiplication and maybe gpus but that's.

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Sebastian Steinhaus: Just ideas at the moment still applying cosmetics to four dimensional models is still very difficult and more work is necessary, mostly because of the limitations that these ideas have, in the sense of.

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Sebastian Steinhaus: That you are dependent very much on the complexity of bonding over spaces, but this completes this part about transcendental meditation I think questions.

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Abhay Vasant Ashtekar: yeah I got a couple of questions on that slide that you just now have here.

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Abhay Vasant Ashtekar: You are going to be.

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Abhay Vasant Ashtekar: The last time we talked about confining end confining and then talk, talk about this and look, but I thought that confining deconstruct final week and finding phases, we were defined by just the be able to the bills and loop right that goes like area or.

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Sebastian Steinhaus: Exactly yeah yeah.

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Abhay Vasant Ashtekar: So, so is it's a okay.

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Sebastian Steinhaus: So it's just it's just to show that.

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Sebastian Steinhaus: makes the argument that made before that you can you know first cost rate and then measure your observable and approximate it well works in the setting is.

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Abhay Vasant Ashtekar: Doing that you're you're sort of changing the coupling costume is that right, I mean this procedure.

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Sebastian Steinhaus: Exactly i'm well i'm not saying the coupling points and just happen and effective theory now right, so if we normalize the amplitude and I just have some effective theory which is not necessarily have the same form as the original.

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Okay.

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Abhay Vasant Ashtekar: So that's okay so, then what says the coupling costs and running.

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Sebastian Steinhaus: And the company constant, you could say that it's running if you're trying to project back to the original theory space, which is something you can do.

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Abhay Vasant Ashtekar: What do you mean by that I mean I got an audience is of is the final one and then next one is the course or one.

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Abhay Vasant Ashtekar: You know I got a fixed coupling constant, which was really good and let's find the theory.

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Abhay Vasant Ashtekar: And you just have a different theory so in a different theory I don't have the same coupling constant So what does it mean to say Copernicus and France.

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Sebastian Steinhaus: So.

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Sebastian Steinhaus: So the idea would be that you start with your initial theory, for which you pick a couple of constant you were normalized once.

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Sebastian Steinhaus: And then you have a new theory which is, in principle, just more general direction we're in sort of the same form anymore, but what you can try it is to define a prediction back to the original series space in the sense that.

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Sebastian Steinhaus: You have right back at the original theory wasn't with every normalized with the new couple of concept.

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Abhay Vasant Ashtekar: Just that makes sense yeah he said, let me guess procedure.

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Sebastian Steinhaus: I mean, because it no it's not no it's not.

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Sebastian Steinhaus: Okay, so they're running is not at all.

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Abhay Vasant Ashtekar: it's not a.

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Sebastian Steinhaus: Year it's just.

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Abhay Vasant Ashtekar: it's not running would just be interested here.

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Sebastian Steinhaus: We do not have an active way of tracking This is just.

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Abhay Vasant Ashtekar: Okay, and so this is the same same thing is going to happen in gravity right in the sense that not changing any coupling constants so you just start saying that you got a different theory.

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Exactly.

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Abhay Vasant Ashtekar: level.

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Sebastian Steinhaus: But.

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Abhay Vasant Ashtekar: But, but ultimately the course when level, we have a newton's constant, which is given to us right, I mean in the real world.

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Abhay Vasant Ashtekar: So, but, but you got a much more complicated theory which is not not the same as the usual theory, so what is the relation between many, many terms in this coarse grained new kitty and say you know just general classical dinner duty or something.

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Sebastian Steinhaus: Yes, that's indeed a very good question um at the moment, I would just be happy if you could connect back to generativity in one way or another, you wish, it would be for another.

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Sebastian Steinhaus: Helping constant but.

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Sebastian Steinhaus: You know one scenario that you could imagine is if we can kind of connect to an effective quantum field theory, it could be that we.

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Sebastian Steinhaus: That we might be able to connect you notice a spin forms rpg something that hasn't public safety right that you somehow come up as some specific point in.

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Sebastian Steinhaus: You know, in the face of the space of the series space instance of coupling constants and that we somehow mean this just once an hour it's very, very difficult to show, but this is something that I could imagine.

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Abhay Vasant Ashtekar: All that you're doing utility is not general relativity generally agree with many, many editing higher higher which terms and with higher curvature I met a couple of concerns it just that those effects are suppressed for the observable that you measure is that is that a possibility.

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Sebastian Steinhaus: Possible yeah that could also be that's one potential outcome, yes, yes.

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Abhay Vasant Ashtekar: Okay, so this is all work in progress, I mean there's not the view, even the conceptual viewpoint is still floating is not on.

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Sebastian Steinhaus: Yes, I would definitely say so yeah.

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Abhay Vasant Ashtekar: Thank you.

316
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Sebastian Steinhaus: But this was still fix this could still you know connect to as public safety in that regard to there you can also have you know.

317
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Sebastian Steinhaus: Higher curvature trends.

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Abhay Vasant Ashtekar: Like but it's.

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Sebastian Steinhaus: But there's also like a mean, as far as I understand it, hasn't received is also just always be rotated so I wouldn't know what the impact of that would be yes.

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Abhay Vasant Ashtekar: Many issues.

321
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Sebastian Steinhaus: But you know let's say that if we could make connection to some effective on a few theory.

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Sebastian Steinhaus: I think that would already be amazing.

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Yes.

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Sebastian Steinhaus: I think many, many continuing physicists would be so happy if we could come up with something like this.

325
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Abhay Vasant Ashtekar: I get it, I get it.

326
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Sebastian Steinhaus: But I don't see how this could emerge at this current state.

327
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Sebastian Steinhaus: Okay, so.

328
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Sebastian Steinhaus: let's talk about the last topic of this.

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Sebastian Steinhaus: Facility, which is the restricted semi classical for smartphones so because it is a difficult to tackle for the nation's most tense networks and Benjamin by myself thought about the strategy, but how we can access the full spectrum of integral.

330
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Sebastian Steinhaus: But maybe just certain subset of it, so the idea was that we, for example, takes the fourth dimensional model define it on a per cubic too complex in the.

331
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Sebastian Steinhaus: K l extension and i'm just restrict the shape of the intertwine us so it's of course not realistic, more than whatsoever, but what we tried, for example, was defining coherent se to intertwine is that a peach on the shape of shape.

332
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Sebastian Steinhaus: When, of course, very drastic simplification, because you do not some of the intertwines anymore you just have very few presentations late with presentation labels that you actually sign over.

333
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Sebastian Steinhaus: But it is.

334
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Sebastian Steinhaus: It is one attempt to access the four fundamental particle and we didn't use for them to to we just used as an expansion and.

335
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Sebastian Steinhaus: So, as usual, as you as you compute the asthma expansion is just you take your coherence states, he exponentially age.

336
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Sebastian Steinhaus: The contractions a coherent states and then you perform it as the six new face approximation.

337
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Sebastian Steinhaus: One thing I must mention is, for example, the face altitude, which we have modified back then so we've included this exponential alpha which is reflecting the that.

338
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Sebastian Steinhaus: There can be some ambiguity in terms of choosing the space amplitude and it's the scaling behavior is actually very important and.

339
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Sebastian Steinhaus: Especially phase approximation is incredibly simple so, in contrast to usually you don't have a cosine anymore to cross the reaction through associated with this.

340
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Sebastian Steinhaus: configuration always finishes and basically you get flooded building blocks that are glued together in a flat way and essentially it's just a superposition.

341
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Sebastian Steinhaus: Of hyper cuboid of satellite offices and it's just corresponds to different subdivisions of FLEX facetime so it's not realistic whatsoever, but.

342
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Sebastian Steinhaus: At least it has something that you could say, and the beauty and subclass of the few more items, so if you move into hyper planes.

343
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Sebastian Steinhaus: In these hyper keep warning letters, it should actually correspond to a different office and because.

344
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Sebastian Steinhaus: It shouldn't matter how you subdivide just based on that the symmetry is broken, and you can you can kind of restore it if you to an alpha accordingly.

345
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Sebastian Steinhaus: What we did was reef in this in the PL from 16 we've actually studied like an observable which is just the variants of volume that is subdivided between two cubes.

346
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Sebastian Steinhaus: On a course and then find setting and asked what, how do we have to choose our company constants for these observable to agree.

347
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Sebastian Steinhaus: and refuse this, for example, to define a realization will flow here, for example by comparing these two curves so that's, of course, in a sense.

348
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Sebastian Steinhaus: A bit of cheating because usually wants to compare your states in your physician aptitudes and you, of course, demand that you observe what's the grease have you put an.

349
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Sebastian Steinhaus: inverted this.

350
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Sebastian Steinhaus: argument missing one or observable still agree with these settings but we use it to define realization good flow and here we really saw that there are indications for UV attractive fixed points.

351
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Sebastian Steinhaus: And the parameter was actually quite close, for which the symmetry was restored so we've treated this as a proof of principle, of course, is a very simplified model and.

352
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Sebastian Steinhaus: fall away from the fourth part integrals but, nevertheless, this model as simple as it is as a test scenario for exploring other situations and Just to give you, for example, so.

353
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Sebastian Steinhaus: This was expanded to more general shape so called Forrester, which you can imagine, to be like four dimensional trapezoid.

354
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Sebastian Steinhaus: with which you can model expanding and contracting tribulations and even the Andrea ization it's just a test case, for example, to study observable and develop new methods and tools and.

355
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Sebastian Steinhaus: One work they did, together with your Highness Julian was to study at fusion draws on the space time in which you could compute the spectral dimension.

356
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Sebastian Steinhaus: Of the sprint phone and depending on this parameter Alfonso in the face of attitude and we could, for example, define or we could.

357
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Sebastian Steinhaus: be found spend foremost that can have a dimension, a spectral dimension that is between zero and four, and this was closely related to the skating behavior of the attitudes.

358
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Sebastian Steinhaus: and new projects in terms of realization is one thing that i've worked on, with my PhD student just its mouth is starting to rent and smartphones so i'm looking at kind of putting your time like faces and taking the results by.

359
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Sebastian Steinhaus: Kaminski lawsky enzyme on and also have a view towards the future case and I want to re examine this realization with frost is key points.

360
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Sebastian Steinhaus: Beyond looking at observable, but I want to use this chance now to talk about two new projects and the first one is with.

361
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Sebastian Steinhaus: A at least from the master student and Courtney Allen at you want a new on or she's not you gals and Florida juggling and pick actually computed this.

362
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Sebastian Steinhaus: verse amplitude for the few points in the quantum machine, so we actually did a very similar calculation to the calculations for the Rentals but for models by.

363
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Sebastian Steinhaus: From the people from a say and.

364
00:54:25,620 --> 00:54:34,560
Sebastian Steinhaus: Of course, this is just what I see in the Romanian setting and this, of course, in that regard much simpler, it is more difficult because we have higher been building blocks.

365
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Sebastian Steinhaus: which also explains why we can only go for up to something excellent for, but what we did we actually wanted to compare.

366
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Sebastian Steinhaus: The semi classical amateur, to the point and attitude so, for example, this is where all the spins of the bbq by are the same, so we see already a nice convergence of semi classical results for the quantum results so.

367
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Sebastian Steinhaus: Actually, like but yeah semi classical songs overestimates, at least for small spends the quantum result, also the articles doesn't show any oscillations and stuffs the semi classical amplitude and another one that interested me.

368
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Sebastian Steinhaus: A bit more or I should say so on the left hand side and i'm very confident that if you could go to spend 10, for example, that that.

369
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Sebastian Steinhaus: The corner, which would be a very good approximation of the semi classical one on the right hand side is a bit more interesting because it concerns about when does the.

370
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Sebastian Steinhaus: quarter regime transition to the statistical machine because we've taken basically five spin small and a different settings so basically once will not so this one spin that is very largest is here on the X axis and the first side is, for example on.

371
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Sebastian Steinhaus: Another spin spin one half So you see that there's a rather big gap between like the semi class the quantum ambiguity and orange and the blue one is classical one and doesn't it very slowly add more only gets less and then, as we increase, for example, these these five spins a bit.

372
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Sebastian Steinhaus: that the gap between semi classical quantum amplitude some small this on a logarithmic scale on the next slide you can see, actually the relative error, so the error that the semi classical amplitude has with respect to.

373
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Sebastian Steinhaus: The quantum one and even the left hand side will often say equal it into drops nicely So here we are already at roughly like 40% error, but on the right hand side if, for example, or spits out one half.

374
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Sebastian Steinhaus: You even if you go to spend like 30 you are.

375
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Sebastian Steinhaus: For this one large span actually add us to like 300% error and but it drops of increasingly so, as you increase the other spins and.

376
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Sebastian Steinhaus: Here, but this is still around 50% error, so why can't be going higher well.

377
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Sebastian Steinhaus: hyper cubic sprint formulas and much more costly than for simplicity, so he will make it back of the envelope calculation to just you know just manually contract intertwine us.

378
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Sebastian Steinhaus: For example, if you have spins four and a half we're happy to point.

379
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Sebastian Steinhaus: The amount of calculators you have to do, for that is roughly the same as being spent 44 for simplex so that is actually something which is deterring the pitch for but continuing with working with coupons.

380
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Sebastian Steinhaus: and

381
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Sebastian Steinhaus: But so it's it's interesting to see that also in these models this.

382
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Sebastian Steinhaus: That you know you see the that the semi classical approximation gets better and yeah now again a different change of pace is the last part is talking to me about what we can, maybe do about Netherlands.

383
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Sebastian Steinhaus: from us, so if they exist different ideas, how we can incorporate methods went from quantum gravity so many approaches and number four One of those is basically putting that on top of it.

384
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Sebastian Steinhaus: The X is also unification scenarios and sometimes So the idea of massive scale of fields, for example, to permit Fries.

385
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Sebastian Steinhaus: But the question is like basic voices next of the combined system that's what i'm interested in and.

386
00:58:22,260 --> 00:58:28,440
Sebastian Steinhaus: Basically, a few years ago I started with a model where just had a two dimensional using model that was couples to Alex been for model.

387
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Sebastian Steinhaus: And was essentially in the middle of a couple of ways, so I said that the evening couple be true depend on the geometry according to spend for model.

388
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Sebastian Steinhaus: And then, using cancer networks, I will normalize both systems, I found the face diagram on the left hand side, which is essentially just a product face diagram so you basically have the two phases, that the.

389
00:58:48,270 --> 00:58:54,270
Sebastian Steinhaus: The analog spin form at the eastern world can be in and there's The thing that I want to emphasize here is.

390
00:58:54,780 --> 00:59:02,880
Sebastian Steinhaus: That by basically tuning the coupling constant of the easy more you can drive geometric faces, so we can force the system from some to take smaller links.

391
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Sebastian Steinhaus: And I think this is very interesting because in the end us what we should do is, if we add matter to spin forms, we have much more minorities, so we eventually must will normalize the combined system and the question is, and this, for example, isn't something that string theorists.

392
00:59:21,030 --> 00:59:33,450
Sebastian Steinhaus: ask us often or yeah like How does quantum gravity actually affect the metal sector so, for example, would be spin forms compatible with the Center for sits at the moment that's a question that is.

393
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Sebastian Steinhaus: I mean, I cannot answer, but it would be interesting to see what happens and when a bit of a benchmark on experience and as a public safety, where they can make statements about this.

394
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Sebastian Steinhaus: And i'm currently investigating together with muscle minor league of coupling investors in a field to a restricted for dimension sprint phone so.

395
00:59:53,580 --> 01:00:08,760
Sebastian Steinhaus: I just want to flash this briefly here, basically, if you can write this gator field in terms of forms and uses discrete extremely accomplished, you can define a scaffold action on a regular basis, this is nothing new it's just even just.

396
01:00:10,350 --> 01:00:13,380
Sebastian Steinhaus: This is nothing new, and I think most of you are very familiar with this.

397
01:00:14,580 --> 01:00:22,290
Sebastian Steinhaus: Actually, because that just to see the field action that you get from this this actually rather straightforward to define so, for example, for the diagonal parts.

398
01:00:22,650 --> 01:00:28,920
Sebastian Steinhaus: You get some parts of which you assigned to the edges so Sigma one basically to the edges you assign.

399
01:00:29,250 --> 01:00:45,480
Sebastian Steinhaus: Something but just the volume dual to the to the to this length divided by the length of the legs itself, and then the master times the total volume of a vertex so that's it for you and the alternate grew apart, is just minus this part over here.

400
01:00:46,620 --> 01:00:52,950
Sebastian Steinhaus: And Basically, this is now at this good food actually defined for an irregular letters principal.

401
01:00:54,180 --> 01:00:54,780
Sebastian Steinhaus: and

402
01:00:55,950 --> 01:01:03,330
Sebastian Steinhaus: Then just a couple days to spend for model by taking this metric action and further length from the sprint for model and.

403
01:01:04,440 --> 01:01:08,460
Sebastian Steinhaus: Half the actors, the Meta party vic rotate analyst APP does this is a strong assumption.

404
01:01:08,940 --> 01:01:14,520
Sebastian Steinhaus: And times to spend from attitude and I integrate over the length of the sprint phone I integrate over the fields.

405
01:01:14,910 --> 01:01:23,880
Sebastian Steinhaus: And now a bunch of study observers, this could be, for example, geometrical level so for this expectation length, what is the expectation, like the volume and.

406
01:01:24,840 --> 01:01:30,750
Sebastian Steinhaus: I would also like to know what other colleagues have a scale of field, and this, of course, very difficult question, so what I actually like.

407
01:01:31,230 --> 01:01:37,350
Sebastian Steinhaus: Different more for some invariant of servers and the setting vertical off the scale of fields right so because.

408
01:01:37,950 --> 01:01:46,440
Sebastian Steinhaus: coordinate dependent expressions of this call later i'm not sure if you move as an invariant but, for example, the existence suggestion and finding the cdt review.

409
01:01:46,860 --> 01:01:51,900
Sebastian Steinhaus: Where you define the coordinator of the scale of field separated by God, sick distance.

410
01:01:52,680 --> 01:02:09,480
Sebastian Steinhaus: Because the continuum expression would be that you compute the call later the medical later for effect for a specific metric and fix the distance between X and white, be the Judy citizens are and then integrate over all possible points and all metrics.

411
01:02:10,500 --> 01:02:20,190
Sebastian Steinhaus: And this is something trying to implement into small here we're basically just spit from well it's just coupled with active the massive free skein of fields.

412
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Sebastian Steinhaus: is coupled to ethical position of Barbecue boydell legacies which elevated by the spirit from the Center testicles Muslim aptitudes and just as a sneak peek before I close, is for example here is the volume expectation value.

413
01:02:37,170 --> 01:02:44,010
Sebastian Steinhaus: off of this, for example, so alpha is again this parameter in the face amplitude that essentially determines for you.

414
01:02:44,730 --> 01:02:54,870
Sebastian Steinhaus: whether small or large segments are preferred, and this is here for one specific mass so what you see here is essentially if I choose offer to be small.

415
01:02:55,620 --> 01:03:04,800
Sebastian Steinhaus: Basically, enter the lower cut off of the model if I choose alpha to be large and then the upper cut of of the model, but you just have to define order to make this thing work in terms of what the Coliseum nations.

416
01:03:05,340 --> 01:03:12,900
Sebastian Steinhaus: But the existing to me is regime in which basically matter pot and spin from current balance each other out we've got some finance volume.

417
01:03:13,920 --> 01:03:23,520
Sebastian Steinhaus: So the question would be does put a quick matter play a role for example lessening at least the infrared emergencies of suspenseful and.

418
01:03:24,120 --> 01:03:38,100
Sebastian Steinhaus: If you look at the variants of for for volume and you divided by the exploitation of for volume there seem to be like you know, two peaks in this which could indicate phase transitions, which are precisely matching to these.

419
01:03:38,880 --> 01:03:49,890
Sebastian Steinhaus: On sets of this, you know the steep ascent here, and here, so the question would be is there actually a face rendition of this matter gravity system, but we need.

420
01:03:50,430 --> 01:03:59,880
Sebastian Steinhaus: to study this in more detail before we can say anything conclusive, but at least it looks encouraging and I should add this all done for Perry boundary conditions, so there is no boundaries this.

421
01:04:00,780 --> 01:04:10,230
Sebastian Steinhaus: example here so it's just a close compact universe, so let me come to my summary so today, I tried to give you a brief introduction to spin for models.

422
01:04:10,830 --> 01:04:18,630
Sebastian Steinhaus: and tell you that they define owner so yet too complex, which serves as a regulator and you get cornered tools for these quantum too much box.

423
01:04:19,560 --> 01:04:25,980
Sebastian Steinhaus: I explained back when the pendulum ization were contemplating and where the ideas that you relate transitions.

424
01:04:26,430 --> 01:04:37,020
Sebastian Steinhaus: On different boundaries were betting maps and it has to go towards efficient combinations and possibilities for operating costs observers, and one way to do this was, for example, this.

425
01:04:37,830 --> 01:04:46,350
Sebastian Steinhaus: Transnational to normalization were present we briefly talked about this fusion basis for three dimensional escapes theories, we find 400 groups where the.

426
01:04:46,770 --> 01:04:59,160
Sebastian Steinhaus: fans face interaction between the confining confining Phase four five Kate and the second one was about the restricted semi classical profitable, we found this indications for your V attractive fixed points.

427
01:05:00,210 --> 01:05:09,030
Sebastian Steinhaus: I talked about the various them to do the quantum machines and briefly flashed that we want a couple of massive scale of field, the substitution for.

428
01:05:09,660 --> 01:05:19,680
Sebastian Steinhaus: But I want you, whatever, but I hope that I could convince you is that this course is essential to transmit forms into a computation framework, but we can make sure that actually our our.

429
01:05:21,180 --> 01:05:33,510
Sebastian Steinhaus: Our predictions are consistent and as a bit of an outlook, I think I want to emphasize again that the was this very encouraging progress and spent four months in the last few.

430
01:05:34,890 --> 01:05:39,600
Sebastian Steinhaus: months and years, we have to send out an algorithm to compute the various amplitude.

431
01:05:40,860 --> 01:05:56,400
Sebastian Steinhaus: It seems, which was also part of this reason I could, yes, that seems to be emerging consensus about the factors problem, the trends in America and the SMS magic formula, because it seems now that in America, you can see an.

432
01:05:59,160 --> 01:06:04,140
Sebastian Steinhaus: Slow exponential suppression of curve geometries.

433
01:06:05,190 --> 01:06:06,510
Sebastian Steinhaus: But it seems to be a slow.

434
01:06:07,680 --> 01:06:20,610
Sebastian Steinhaus: I there's, of course, the effect of spin for model which allows you to explore much lot of translations and they are now luscious doubles and Monte Carlo Markov chain Monte Carlo simulations to compute observers with those and.

435
01:06:21,990 --> 01:06:32,730
Sebastian Steinhaus: I think these new tools are very important, if you want to call screening, because they are tools actually compute the amateurs which is one key component to to actually get going on screen.

436
01:06:33,240 --> 01:06:39,870
Sebastian Steinhaus: And I also think that we must explore the rental sector, so what I discussed it for was mostly reminding you must go to the events in sector.

437
01:06:41,040 --> 01:06:47,280
Sebastian Steinhaus: and include matter couple of the sprint for models and what I do, that I want to explore them in the future is.

438
01:06:47,790 --> 01:06:55,890
Sebastian Steinhaus: Actually, using spin from attitudes themselves as embedding that's just an idea that the anchor myself propose some time ago because.

439
01:06:56,640 --> 01:07:06,690
Sebastian Steinhaus: You can imagine that under evolution, you can go from one state to another, and you have different amounts of degrees of freedom So yes, but from attitudes that describes for you.

440
01:07:07,500 --> 01:07:20,820
Sebastian Steinhaus: How degrees of freedom I added or removed, and of course they are dynamic continental theory, this would be identical embedding that just that, as an APP from by one space to another, but I.

441
01:07:21,600 --> 01:07:27,270
Sebastian Steinhaus: have to work more on this before I can turn anything was, but at this point that we stop, and thank you for your attention.

442
01:07:37,470 --> 01:07:38,100
Jorge Pullin: The questions.

443
01:07:50,910 --> 01:08:02,790
Carlo Rovelli: it's a it's Vegas or indirectly related but it's a it's a question whether your exploration this direction, can can tell us something in another direction in this in this last.

444
01:08:03,930 --> 01:08:06,150
Carlo Rovelli: slide the outlook that that you have.

445
01:08:07,470 --> 01:08:15,180
Carlo Rovelli: You mentioned the recent sort of some steps of clarification, towards the so called slackness prob problem that.

446
01:08:16,260 --> 01:08:16,980
Carlo Rovelli: I agree there is.

447
01:08:18,240 --> 01:08:33,990
Carlo Rovelli: The new information coming in and and i'm trying to get some clarity about that, and the question is the following um one way of viewing the issue is to to think that.

448
01:08:35,490 --> 01:08:39,060
Carlo Rovelli: The amplitude the works in the.

449
01:08:40,320 --> 01:08:45,540
Carlo Rovelli: I mean what one cannot take the large spin limit without together, taking the.

450
01:08:46,740 --> 01:08:52,950
Carlo Rovelli: The sufficiently fine refinement refinement that's that's if you want the.

451
01:08:54,450 --> 01:08:59,100
Carlo Rovelli: machine way of viewing this the the.

452
01:09:00,120 --> 01:09:10,050
Carlo Rovelli: The classical theory comes out what comes out in in a suitable limit in which you, you don't truncate at the same time you go to large speed.

453
01:09:11,070 --> 01:09:15,870
Carlo Rovelli: that's that's it's clear it's one possibility it's it's Okay, but there's another.

454
01:09:17,340 --> 01:09:20,190
Carlo Rovelli: set of papers that.

455
01:09:21,300 --> 01:09:27,990
Carlo Rovelli: say something similar in spirit but different in practice, which is the the old works of.

456
01:09:29,550 --> 01:09:32,910
Carlo Rovelli: The polynomial yo and the end the recent work by.

457
01:09:34,620 --> 01:09:41,670
Carlo Rovelli: How and bianca it we just sent you to say yeah you can do exactly the same thing, but you don't need to go to the.

458
01:09:43,590 --> 01:09:46,110
Carlo Rovelli: refinement you can do the same on a fixed set the.

459
01:09:49,140 --> 01:09:49,860
Carlo Rovelli: owner fix that.

460
01:09:53,160 --> 01:09:56,580
Carlo Rovelli: too complex, provided that you take gamma.

461
01:09:58,020 --> 01:10:06,900
Carlo Rovelli: Small at the same time, so you you you do this is a it's an old lady I keep coming back, I think I suppose time i've seen it in the old paper but cloud you're.

462
01:10:07,560 --> 01:10:18,930
Carlo Rovelli: In a Lena long ago in which they prove that they call the what is the fluid limit or something like that, in which you, you by taking that limit also you get they get the ice and equations in fact out of them.

463
01:10:21,000 --> 01:10:25,620
Carlo Rovelli: Now what one thing is not clear to me is how these two things are related.

464
01:10:26,850 --> 01:10:35,430
Carlo Rovelli: Because they seem to be saying the same thing, but they're they're literally they're the same very different things, so it was wondering whether your perspective.

465
01:10:36,930 --> 01:10:42,180
Carlo Rovelli: could be actually way of joining the two things and the specific question is.

466
01:10:44,580 --> 01:10:52,950
Carlo Rovelli: If I take the the the this before amplitude it has a parameter, which is gamma, which is a fixed parameter, the way we.

467
01:10:54,210 --> 01:11:17,520
Carlo Rovelli: We think about it, and, of course, if I do if I now put this basket happen on my head yeah I immediately asked the question, oh great so here, I have a parameter, and the first question is, how does it scale and you have ways of of thinking about how it scales and a priority, so.

468
01:11:19,320 --> 01:11:23,670
Carlo Rovelli: Now I so far is just facts now let me jump into.

469
01:11:25,050 --> 01:11:29,670
Carlo Rovelli: into questions and possibilities speculations maybe the two things are the same just because.

470
01:11:31,440 --> 01:11:36,360
Carlo Rovelli: When I scale up it's it's really gamma that becomes smaller.

471
01:11:37,440 --> 01:11:38,370
Carlo Rovelli: up or down depending.

472
01:11:40,710 --> 01:11:45,270
Carlo Rovelli: And so, so with which is sort of.

473
01:11:47,970 --> 01:11:56,310
Carlo Rovelli: Not implausible intuitively because when you will find it in relation, of course, a given boundary data you expect that.

474
01:11:58,260 --> 01:12:02,340
Carlo Rovelli: The classical solution is given on on on.

475
01:12:04,290 --> 01:12:20,220
Carlo Rovelli: triangulation switch or small small angles, and we know that the sort of accidental constraint, which was given the flatness is suppressed when you go to to to small read angles.

476
01:12:21,780 --> 01:12:40,080
Carlo Rovelli: I think you see what i'm saying is it's not just a question or could could could something like that be the actual phenomena that connects the two sort of the two the two limits in which, in which we get the in which we get the classical theory, in a sense, you know it.

477
01:12:41,280 --> 01:12:47,730
Carlo Rovelli: It was a disappointment, but I am still going around it i'm still trying to say it wasn't disappointed with the idea that.

478
01:12:49,410 --> 01:12:59,580
Carlo Rovelli: It seems wrong, even if i'm not entirely convinced, yet, but it's it seems wrong that if you fix it a relation and you take the large speed limit on the boundary.

479
01:13:00,450 --> 01:13:07,170
Carlo Rovelli: You don't get a ranger few you get a registry corrected the with with accidental constraint.

480
01:13:08,040 --> 01:13:26,790
Carlo Rovelli: So, to get the classical theory, you cannot do that step, you have to go together the step of the refining refining and the and the lunch speed so could it be that would your your method connect the two ways of doing this correctly me to go to the classical theory.

481
01:13:30,060 --> 01:13:46,470
Sebastian Steinhaus: They could certainly be a possibility that you know the things that come up as a parameter, of course, it should run was so far not possible, we need to do this because be looked at the remaining theory and there it's you have lots of difficulties because comma comma especial.

482
01:13:48,060 --> 01:13:57,660
Sebastian Steinhaus: So that it wasn't possible, and you know, in many ways, Washington again is very appealing, because it connects, of course, to the old continued limiting in venture capitalists.

483
01:13:58,680 --> 01:14:06,000
Sebastian Steinhaus: So if I could of course do this, this is very great, I am just always a bit concerned about.

484
01:14:06,780 --> 01:14:19,080
Sebastian Steinhaus: Then you have to do many assumptions for for this construction costs, you have to talk about in what kind of machine your spins should be for this to work, and I think this is where the problem still is right.

485
01:14:20,520 --> 01:14:34,320
Sebastian Steinhaus: Also there's also a problem with the launch day limit, because a priori, we do not know which spins actually contribute the most and if you're if you have something over over data, then of course cannot really say that.

486
01:14:36,600 --> 01:14:47,880
Sebastian Steinhaus: But it might be that there as an effective theory, some of these issues may not occur that you know if you weren't able to some over some that you have.

487
01:14:48,960 --> 01:14:51,090
Sebastian Steinhaus: You know finance theory.

488
01:14:53,280 --> 01:15:01,470
Sebastian Steinhaus: which runs on the configurations dominate were just you have just maybe small deficit angles arrive at a more effective theory.

489
01:15:01,980 --> 01:15:12,030
Sebastian Steinhaus: Where you don't have the excellence of kosher constraint anymore, let me it's conceivable I don't know it's speculation at this point and the connection to DEMO, I think, is something that we should look into.

490
01:15:12,720 --> 01:15:21,690
Sebastian Steinhaus: A bit further, because as far as I understand it, dharma has a record related, for example, to the effect of spin for models of stephanie unkind hell.

491
01:15:23,220 --> 01:15:37,770
Sebastian Steinhaus: To the implementation of the constraints and they argue that you have this this washing out of the simplicity constraints in a way of depending on how large areas is and also the choice of.

492
01:15:38,580 --> 01:15:39,150
Carlo Rovelli: Exactly.

493
01:15:39,450 --> 01:15:53,940
Sebastian Steinhaus: And if you make a smaller than these washing out effect is less so, I think that could be definitely a revelation of that, and it is probably would, if you just think about brutalization there could be a case where.

494
01:15:55,290 --> 01:16:05,760
Sebastian Steinhaus: You know, for example, you have a series which, for example, and flow come up with effectively increase another direction that could decrease, which could differentiate different very different regimes of the series.

495
01:16:06,330 --> 01:16:13,350
Sebastian Steinhaus: yeah these things are conceivable it's conceivable that these are late in such a way, but I must say it's very it's just speculation at this point.

496
01:16:14,370 --> 01:16:14,790
Carlo Rovelli: Thanks.

497
01:16:15,600 --> 01:16:16,890
Jorge Pullin: Tomorrow, you have your hand raised.

498
01:16:17,670 --> 01:16:18,330
Simone SPEZIALE: Yes, thanks.

499
01:16:19,920 --> 01:16:31,290
Simone SPEZIALE: Two questions so The first one is that i'm impressed that you were able to do medical simulations with the cuboid which I can't believe it's much harder, and so I was wondering if.

500
01:16:31,620 --> 01:16:33,690
Sebastian Steinhaus: It goes to to our master student.

501
01:16:34,290 --> 01:16:35,460
Simone SPEZIALE: Well, great.

502
01:16:36,840 --> 01:16:52,590
Simone SPEZIALE: I was wondering, it will you show that it's quite hard to do, but you know that we should we Peter that there are these other types of critical configurations, in the case of politics, which are not for simply sees and like these.

503
01:16:53,700 --> 01:17:02,100
Simone SPEZIALE: geometries that are reggie up to confirm transformations the match the angles, but not necessarily the edges, I was wondering if.

504
01:17:02,790 --> 01:17:17,580
Simone SPEZIALE: It would be possible with your metrics to check these resulted to see numerically the presence of critical behavior with such configurations, which are not necessarily ranger or whether that's too hard.

505
01:17:20,490 --> 01:17:29,820
Sebastian Steinhaus: Probably we couldn't go to not spend I mean probably over there at the moment is very much written towards this specific case of the keyboards.

506
01:17:32,040 --> 01:17:32,670
Sebastian Steinhaus: If you can.

507
01:17:34,380 --> 01:17:46,740
Sebastian Steinhaus: So let me say it this way, so what we did actually was directly compute the intertwine us so and then just contract with them, the idea being that although contraction is costly.

508
01:17:47,550 --> 01:17:58,290
Sebastian Steinhaus: We just want to do it once for specific intertwine us actually computing dinner twice also very costly, if you do it via integration, but in principle it as possible just.

509
01:17:59,430 --> 01:18:01,680
Sebastian Steinhaus: We would have to modify the code and.

510
01:18:04,020 --> 01:18:07,950
Sebastian Steinhaus: It going to much higher latency problem is not a good idea right.

511
01:18:11,010 --> 01:18:12,480
Sebastian Steinhaus: Because it makes things worse.

512
01:18:14,100 --> 01:18:19,950
Simone SPEZIALE: I see Okay, but because also there was the possibility that in some situations.

513
01:18:21,240 --> 01:18:31,500
Simone SPEZIALE: Such geometry is could be used to describe curved the poly tops and it will be interesting to see, we were not able to.

514
01:18:32,460 --> 01:18:48,480
Simone SPEZIALE: Well, make sure that that's always possible, and in fact that the recent developments on the flatness show a counter example, and so it would be nice to maybe have some help from the new metrics that's why I was intrigued by the fact that you may actually be getting there and.

515
01:18:49,530 --> 01:19:07,560
Simone SPEZIALE: The second question is a question i've asked you already in the past, and you know I always wonder, because these alpha parameter, you are there you go also added the BF theory and they always wonder if you could see qualitative differences between the normalization flows, you see.

516
01:19:08,760 --> 01:19:09,690
Simone SPEZIALE: In decades.

517
01:19:09,780 --> 01:19:10,920
Simone SPEZIALE: Compared to.

518
01:19:10,980 --> 01:19:17,070
Simone SPEZIALE: The normalization flow with the EPL because, for instance, if it turns out, as we are discussing.

519
01:19:17,940 --> 01:19:34,440
Simone SPEZIALE: That there is a an intermediate regime or spins may be playing with gamma in which there is interesting dynamics, maybe that's something that can be able to distinguish this model from other minimization flows into biological models let's see so.

520
01:19:36,090 --> 01:19:43,830
Sebastian Steinhaus: For us yeah, and so I mean I remember asking you those questions and maybe just didn't.

521
01:19:44,790 --> 01:19:56,790
Sebastian Steinhaus: mean just let's brainstorm a bit because in principle it shouldn't it be possible to just maybe we already have the ingredients for St to be F in place right because it just we always did for common less than one.

522
01:19:57,690 --> 01:20:08,130
Sebastian Steinhaus: yeah right so maybe that's that's just you know the contraction of the intertwine us without any particular restrictions on the spin so maybe this disagrees or they're already.

523
01:20:09,420 --> 01:20:13,080
Sebastian Steinhaus: Okay, but then he would have to do it for the quantum analytics right.

524
01:20:13,770 --> 01:20:16,560
Simone SPEZIALE: Exactly the idea would be to do it for the exact template to the.

525
01:20:16,590 --> 01:20:23,310
Simone SPEZIALE: Young furthermore modify the Alpha parameter will break topological importance of the theory.

526
01:20:23,310 --> 01:20:24,480
Sebastian Steinhaus: Mountains, yes.

527
01:20:24,570 --> 01:20:26,640
Simone SPEZIALE: But divert exempted will remain the same.

528
01:20:30,690 --> 01:20:31,920
Simone SPEZIALE: Okay, thank you.

529
01:20:38,490 --> 01:20:40,890
Hongguang Liu: Okay yeah fourth the media.

530
01:20:42,300 --> 01:20:44,910
Hongguang Liu: Something related to kairos question.

531
01:20:46,020 --> 01:20:48,000
Hongguang Liu: He calls me and.

532
01:20:49,080 --> 01:20:55,650
Hongguang Liu: He and the chow Hall, and the machine, where I explore in detail wishing you the idea and we can show that.

533
01:20:56,700 --> 01:21:00,540
Hongguang Liu: To Code, the geometry to contribute to the Enfield actually.

534
01:21:01,980 --> 01:21:11,430
Hongguang Liu: Is I mean it's a contribution to enter to the youth going by manners can rg and multiplies and content that they multiplied so that's the angle Square.

535
01:21:12,360 --> 01:21:22,140
Hongguang Liu: So so somehow, you can see, this contribution to the Enfield you can I mean that to ponder wheel at Cairo said first you can send.

536
01:21:22,890 --> 01:21:32,700
Hongguang Liu: out the state, however small, or equivalent Lee you refine your life is to make of it also sweetest most into contributions this your House and.

537
01:21:33,240 --> 01:21:43,980
Hongguang Liu: I mean very, very critical contribution to the empty field, or you may say comma to pharaoh when it becomes larger it's also become stone in some hot sizzling.

538
01:21:44,430 --> 01:21:45,810
Sebastian Steinhaus: will be related to.

539
01:21:45,900 --> 01:21:54,840
Hongguang Liu: To the raw between between Ghana and and reframing towards the light us yeah and say, can I have a question.

540
01:21:55,170 --> 01:21:55,860
Sebastian Steinhaus: Just for.

541
01:21:56,040 --> 01:22:04,980
Sebastian Steinhaus: me just so So the first part is just on you perform or you look at the model on different translations now when.

542
01:22:05,490 --> 01:22:06,030
Sebastian Steinhaus: You find the.

543
01:22:06,510 --> 01:22:12,630
Hongguang Liu: election is the largest before model on on data on the on the on the model.

544
01:22:13,410 --> 01:22:14,790
Sebastian Steinhaus: So basically the sweet sweet.

545
01:22:17,430 --> 01:22:18,390
Hongguang Liu: it's a sweet in case.

546
01:22:18,420 --> 01:22:24,120
Hongguang Liu: Is the model Duke the bye bye bye Francesco and and appear cortana before.

547
01:22:27,150 --> 01:22:33,240
Hongguang Liu: it's a it's a model is the model with Swiss with three four seems like with start with.

548
01:22:33,330 --> 01:22:36,780
Hongguang Liu: One or two key things to share the wine, the wine triangle.

549
01:22:36,810 --> 01:22:41,940
Sebastian Steinhaus: yeah that's that's that's one configuration in this Lucy yeah yeah.

550
01:22:41,970 --> 01:22:43,710
Hongguang Liu: yeah yeah yes, yes okay.

551
01:22:43,800 --> 01:22:44,370
Sebastian Steinhaus: yeah yeah.

552
01:22:45,540 --> 01:22:46,260
Hongguang Liu: And then.

553
01:22:47,460 --> 01:23:02,070
Hongguang Liu: Maybe I have a question for you, because I think you for the for the 3D model you look at Su to keep saying you have you have a fan and cupboard space and then you can change the level pay to infinity to explore what happened to you.

554
01:23:03,240 --> 01:23:04,680
Sebastian Steinhaus: In life but.

555
01:23:05,700 --> 01:23:06,660
Hongguang Liu: Like yeah yeah.

556
01:23:06,780 --> 01:23:17,550
Hongguang Liu: I think you'd like to, yes, but then for for the screen for model for for for these pay for model we don't have such such quantum good structure, at least for the lead wires.

557
01:23:18,600 --> 01:23:20,310
Hongguang Liu: Without customer to a constant and.

558
01:23:20,340 --> 01:23:20,850
Sebastian Steinhaus: Then.

559
01:23:21,240 --> 01:23:32,100
Hongguang Liu: We always have you been to dimension or cannabis space, but as far as I know this sensor network then renunciation methods they only work for the finance hyperspace right.

560
01:23:32,220 --> 01:23:33,180
Hongguang Liu: Indeed, yes, yes.

561
01:23:33,240 --> 01:23:36,540
Hongguang Liu: always need the truncation for the spin jade but you don't have.

562
01:23:37,560 --> 01:23:44,850
Hongguang Liu: At the I mean I mean nature is mental or fetch vacation all you get the truck at.

563
01:23:46,590 --> 01:23:55,560
Sebastian Steinhaus: At the moment I didn't receive that they are good choices, as such, I mean one thing you could try to do, maybe, if you play around for this.

564
01:23:56,310 --> 01:24:12,090
Sebastian Steinhaus: Face aptitude if you make alpha small enough, you could argue that potentially yama to scan saturated laughs Mr contribute but otherwise I don't see any any good way of doing that, and you may not be an interesting part of the theory with that so.

565
01:24:13,620 --> 01:24:21,240
Sebastian Steinhaus: yeah at the moment I can see how we can work with this, I would have to think more about what how one could apply this.

566
01:24:22,590 --> 01:24:27,330
Sebastian Steinhaus: yeah but it wasn't working it just in any dimensions, you cannot go to just arbitrary.

567
01:24:28,860 --> 01:24:35,970
Sebastian Steinhaus: To include dimensions of spaces, and I mean I think recently that was like last year that was this was, for example.

568
01:24:37,110 --> 01:24:39,060
Sebastian Steinhaus: whale ground rounds this of.

569
01:24:40,320 --> 01:24:45,780
Sebastian Steinhaus: Can let's just say like this it's already dating difficult that you wanted to let us feel theory with.

570
01:24:46,260 --> 01:24:55,140
Sebastian Steinhaus: tense networks, but the sentence, you can find instructions around, so I think that was last year it work by promoter comments I forgot the other awesome afraid.

571
01:24:55,500 --> 01:25:07,800
Sebastian Steinhaus: And we looked at two dimensional scale athlete theory with tense networks okay so sometimes you just have to find a good representation of this and then you can work with us, but somehow you everything must be fine dimensional.

572
01:25:08,850 --> 01:25:10,170
Hongguang Liu: yeah Okay, thank you.

573
01:25:11,070 --> 01:25:11,550
Doing.

574
01:25:14,820 --> 01:25:18,390
Ding Jia: Is the question question about the matter art.

575
01:25:18,930 --> 01:25:26,340
Ding Jia: Maybe some simple questions isn't sure that the the kinematics setup is the same as the reggie calculus.

576
01:25:28,590 --> 01:25:29,130
Sebastian Steinhaus: and

577
01:25:31,380 --> 01:25:32,640
Sebastian Steinhaus: The kinematics the setup is.

578
01:25:34,230 --> 01:25:34,950
Sebastian Steinhaus: It is.

579
01:25:35,010 --> 01:25:48,540
Sebastian Steinhaus: The cemetery and reducing the semi classical spin from amateur to PS and and we we go down from from spins to length, so it is in a sense, victory, but we fixed the angles right so it's everything is hyper Q boydell.

580
01:25:49,260 --> 01:25:52,230
Sebastian Steinhaus: By system that's sentence it's very simple.

581
01:25:52,860 --> 01:25:53,400
Ding Jia: I see.

582
01:25:54,780 --> 01:26:05,940
Ding Jia: and for your integral over l, this is a like integrity over continuous where the values of the other room and it's linear inland not squared.

583
01:26:10,740 --> 01:26:21,000
Ding Jia: So this because he read cocos we have a choice, either we integrate over X squared or into it over that linear length.

584
01:26:21,960 --> 01:26:25,470
Sebastian Steinhaus: yeah you just mentioned campus you also have like all kinds of.

585
01:26:25,830 --> 01:26:27,240
Sebastian Steinhaus: Difficult different choices.

586
01:26:27,270 --> 01:26:28,830
Sebastian Steinhaus: of measures and.

587
01:26:28,890 --> 01:26:29,340
Ding Jia: Right.

588
01:26:29,610 --> 01:26:30,900
Sebastian Steinhaus: person, so you would say.

589
01:26:31,230 --> 01:26:36,390
Sebastian Steinhaus: i'm integrating over links and i'm taking the spin from amplitude as the crest the measure.

590
01:26:37,410 --> 01:26:41,610
Sebastian Steinhaus: For this, so I use the split from construction as a measure and the setup.

591
01:26:43,650 --> 01:26:47,160
Ding Jia: And one thing i'm curious about is know you have.

592
01:26:48,390 --> 01:26:55,920
Ding Jia: In this in this simplified model, the same kinematic goals set up as radical, because what happens if you're just to the pure gravity.

593
01:26:57,000 --> 01:27:00,990
Ding Jia: Without matter which you get some some correspondence to richie coconuts.

594
01:27:01,770 --> 01:27:11,580
Sebastian Steinhaus: It is much simpler than metric Conference, because in this example the lengthy the the edges, are the the the angles on dynamical will be the angles, are just fixed.

595
01:27:14,430 --> 01:27:17,250
Ding Jia: So I would you interpret the results for pure gravity.

596
01:27:18,270 --> 01:27:21,270
Ding Jia: there's something meaningful as a physical quality.

597
01:27:21,420 --> 01:27:24,090
Sebastian Steinhaus: You mean, for example, in the sense of you know.

598
01:27:25,200 --> 01:27:33,240
Sebastian Steinhaus: which links dominate or or maybe if, for example, how this platform looks like or.

599
01:27:34,920 --> 01:27:39,300
Sebastian Steinhaus: Exit for volume, for example, if I do the same, construction, like the boundary conditions.

600
01:27:42,870 --> 01:27:47,760
Ding Jia: just want to get a sense, how to interpret the results with the matter company, so if.

601
01:27:47,940 --> 01:27:54,180
Ding Jia: Okay, if without medical you know what it means for paragraph did I have a sense of it means.

602
01:27:55,680 --> 01:28:01,020
Sebastian Steinhaus: yeah so essentially if you if you choose your alpha parameter differently if you make it very large.

603
01:28:01,290 --> 01:28:15,780
Sebastian Steinhaus: Basically, the largest length contribute the most and she do the same, construction, like you, basically, we are also in the are cut off right, and if you make off a small, if you make it small enough eventually you just end up in the lower cut off just.

604
01:28:16,860 --> 01:28:18,990
Sebastian Steinhaus: Basically, the spin from aptitude is just.

605
01:28:20,790 --> 01:28:26,040
Sebastian Steinhaus: A polynomial so it scales in a very simple way, so this is really.

606
01:28:27,180 --> 01:28:42,390
Sebastian Steinhaus: Very simple there's of course line there's nothing is just scales in a particular way and, depending on how we trust alpha you either have very small length you oh you're very large at some point there's a transition point where essentially all length come with the same weight.

607
01:28:43,530 --> 01:28:57,480
Sebastian Steinhaus: And with the metal parts, so this transition point is somewhere around alpha 0.58 so much smaller so with a metal part it shifts this transition to hire.

608
01:28:58,920 --> 01:29:00,000
Sebastian Steinhaus: So basically.

609
01:29:01,380 --> 01:29:12,030
Sebastian Steinhaus: yeah and and basically yeah it's just too high, and you get this new behavior in between, when you get these intermediate volumes finance volumes and you're not cut off dependent anymore.

610
01:29:13,590 --> 01:29:24,990
Sebastian Steinhaus: So that is basically what changes due to matter and it's also a bit of an extended REACH, but here I would have to say also, we have to see how this changes, for example, if you have more degrees of freedom right if you have.

611
01:29:26,430 --> 01:29:34,470
Sebastian Steinhaus: If you add if you make a lattice larger that's like what we need to determine still, so this is still very early on, because we had to understand how the sampling actually works.

612
01:29:37,020 --> 01:29:43,320
Ding Jia: Okay, maybe I can understand it as a as a prototype model to.

613
01:29:44,550 --> 01:29:47,970
Sebastian Steinhaus: me, yes, it is, it is more of a toy example.

614
01:29:48,270 --> 01:29:50,010
Ding Jia: So what would you handle.

615
01:29:50,280 --> 01:29:56,400
Ding Jia: For we suppose everything goes smoothly what's the end goal for this whole program of metric company.

616
01:29:57,570 --> 01:30:11,880
Sebastian Steinhaus: Why you you start exploring other mental models and what kind of effects it has on spin forms and what are you know we question is what are meaningful observable it's actually which which have several it's actually makes sense in a quantum gravity Meta model, for example.

617
01:30:13,290 --> 01:30:15,150
Sebastian Steinhaus: So what are meaningful observable.

618
01:30:16,590 --> 01:30:25,770
Sebastian Steinhaus: You know into continue, how would you define them, how can you translate into the metal part and what how, how do these two systems actually influence each other that's the.

619
01:30:26,400 --> 01:30:34,380
Ding Jia: Right and to answer this question to you fun to stick with the lens variable or do you need to have another formula for.

620
01:30:36,150 --> 01:30:49,530
Sebastian Steinhaus: Eventually, you want to go to, of course, to the to the first one from and then to solve the sprint from degrees of freedom and then see what happens to do the oscillating i'm assuming it's as it's easier said than done, of course, but that's why actually want to go so.

621
01:30:50,760 --> 01:31:03,780
Sebastian Steinhaus: The question would rather be checking this from different sides, you know one part is starting another mental models other part is actually going beyond the simple model.

622
01:31:04,590 --> 01:31:07,530
Ding Jia: And you use a really terrible for Skinner medical.

623
01:31:08,580 --> 01:31:13,980
Sebastian Steinhaus: And yes, that would be the question, but we are, are there any questions that you will also need to ask so.

624
01:31:15,090 --> 01:31:18,000
Sebastian Steinhaus: When there are many things that come up later point so.

625
01:31:19,560 --> 01:31:37,110
Sebastian Steinhaus: So here the Meta action is defined with respect to the semi classical model So how do you do it if you have a point of geometry, so do you make, for example, the assumption that, for example, the applause operators, you know just define as expectation values of your of your geometric states.

626
01:31:38,880 --> 01:31:55,620
Sebastian Steinhaus: need when there are many assumptions that you have to think about and that come into play here, so it's not obvious whatsoever right, and I mean we also do not know what matter as a plan skills supposed to be it's just the first attempt of seeing whether you know, this can make sense.

627
01:31:57,150 --> 01:32:02,970
Sebastian Steinhaus: And whether you, for example, can define a a continual limit for a couple of minutes for a couple of theory.

628
01:32:06,990 --> 01:32:13,740
Sebastian Steinhaus: And at the moment is, of course, in some sense naive explorations which you want to see, but they can give you anything that makes sense.

629
01:32:15,270 --> 01:32:17,820
Sebastian Steinhaus: And I don't know what this is the right approach or not.

630
01:32:21,150 --> 01:32:22,020
Ding Jia: I find it interesting.

631
01:32:23,370 --> 01:32:31,140
Ding Jia: Maybe even the field for theory, maybe I don't know if it is an area version, maybe this person I don't know.

632
01:32:33,000 --> 01:32:37,050
Ding Jia: I think it's meaningful to the sport is this is simplified models thanks for the answer.

633
01:32:38,610 --> 01:32:40,800
Jorge Pullin: i'm buying hundreds hundreds yeah.

634
01:32:40,830 --> 01:32:49,650
Abhay Vasant Ashtekar: So I just have a quick question really would I mean you said, I emphasize how matter is important, and then you also made.

635
01:32:50,730 --> 01:32:53,820
Abhay Vasant Ashtekar: Reference to us in public safety were very interesting.

636
01:32:56,190 --> 01:33:04,230
Abhay Vasant Ashtekar: results have been obtained in the standard model, using the matter coupling but in a synthetic safety, of course, a matter that the couple is really spinner fields and.

637
01:33:04,290 --> 01:33:05,280
Sebastian Steinhaus: engage with us.

638
01:33:05,850 --> 01:33:13,170
Abhay Vasant Ashtekar: And I would have thought that in in spin forms and our parents look on gravity, it is much easier to have spinner fields and.

639
01:33:13,620 --> 01:33:29,190
Abhay Vasant Ashtekar: engaged fields concept but conceptually than a scale of here so Mike conceptually you can just write down what you know what that should be, and so my question is, why is that not being done, or is it something about lattice or something I mean something about computation laws.

640
01:33:30,420 --> 01:33:31,350
Sebastian Steinhaus: It just plant.

641
01:33:33,660 --> 01:33:35,460
Sebastian Steinhaus: The plant, let me say.

642
01:33:36,720 --> 01:33:37,920
Abhay Vasant Ashtekar: I think conceptually much.

643
01:33:38,970 --> 01:33:43,560
Abhay Vasant Ashtekar: Cleaner footing, you know because, even in and look quantum gravity and.

644
01:33:44,610 --> 01:33:54,660
Abhay Vasant Ashtekar: we're not really about a billion anonymously engaged fields, and we know how to couples benefits, so that would be much more interesting, is it can computationally much harder, I mean.

645
01:33:59,370 --> 01:34:03,120
Sebastian Steinhaus: that's the question I would guess, this could be harder to cover.

646
01:34:05,550 --> 01:34:07,980
Sebastian Steinhaus: Something Maxwell right and because I in fact in the.

647
01:34:08,220 --> 01:34:16,410
Abhay Vasant Ashtekar: Beginning that's what they were doing, and he knows in product safety to understand the battlefield thing for a whole bunch of years they're just doing a billion HP.

648
01:34:17,790 --> 01:34:24,540
Sebastian Steinhaus: yeah so maybe the idea was because, for the spectral dimension project we essentially already had to find a laplacian.

649
01:34:24,990 --> 01:34:40,410
Sebastian Steinhaus: But it wasn't the tool that is but that's basically how I already knew how to define this wasn't just could adapt it and then like usually scale a few theories like one of the first examples you read in any kind of lead escape siri.

650
01:34:41,820 --> 01:34:48,870
Sebastian Steinhaus: script so I just thought let's give that a try and this example is actually very simple, because it can integrate off the scale of field.

651
01:34:50,160 --> 01:34:53,910
Sebastian Steinhaus: Okay, so that is, that is, that is very helpful yeah.

652
01:34:55,920 --> 01:34:56,250
Abhay Vasant Ashtekar: Thank you.

653
01:34:57,600 --> 01:34:58,530
Jorge Pullin: Any other questions.

654
01:35:04,830 --> 01:35:06,270
Jorge Pullin: Oh good thanks again.

655
01:35:11,310 --> 01:35:13,740
Sebastian Steinhaus: Thank you for the questions and Nice discussion.