Jorge Pullin: These words speaker to this manuscript to speak about the search for a tabletop quantum gravity signature.
Christodoulou Marios: Thank you very much.
Christodoulou Marios: Thank you very much for the invitation it's very nice to be back.
Christodoulou Marios: So many people that I haven't seen for some time i've tried to make the seminar interesting as an overview of things i've been thinking about and learned the past few years.
Christodoulou Marios: I realized that my title was a bit too ambitious.
Christodoulou Marios: I wasn't able to feed the many things that are happening, so this is a very personalized.
Christodoulou Marios: selection and of topics around the search for a table top quantum gravity signature.
Christodoulou Marios: So, to give you a quick overview weather will say because I didn't put them took outline i'll start with a, I will start with a short historical note, I give you a summary of some experimental news that you may you may be interested to them with an expert in distinct.
Christodoulou Marios: A quick overview overview of one set up for detecting gravity limited entanglement, which is the simplest conceptually and which I will analyze in the last part.
Christodoulou Marios: And first give an overview of the debate and some confusion, then I will.
Christodoulou Marios: analyze this setup based on our various and paper and take you through it.
Christodoulou Marios: And then finish with a short discussion, these are our small parts.
Christodoulou Marios: The several small parts to talk all right let's start.
Christodoulou Marios: So, first of all, historical note.
Christodoulou Marios: There idea will be talking about.
Christodoulou Marios: detecting entanglement the generated by gravity is not a new idea at all them people have inside the Chapel hill conference.
Christodoulou Marios: Where reject rain man, this is a selection of course that i'm taking from this paper, which is very nice paper from our point of different experimentalists.
Christodoulou Marios: An sc that came out very recently.
Christodoulou Marios: we're in trouble, and it will be live in quantum mechanics been done coindesk of additional theory, one should think about Designing an experiment.
Christodoulou Marios: which uses a gravitational link and at the same time, shows quantum interference, I find very interesting that trace of war of words here, we already alluded to some.
Christodoulou Marios: quantum from patient.
Christodoulou Marios: idea that you wanted wanted practice and bass will come back to that later.
Christodoulou Marios: So there is an exchange where we wheaton asks what prevents this from becoming a practical experiment.
Christodoulou Marios: And Richard feynman says, you might argue this way somewhere in your part to this idea of credibility amplitude has been lost.
Christodoulou Marios: You do not need it anymore, so you drop it the wave packet would be reduced or something even though you don't know where it's reduced it's reduced, and then you can do an experiment which distinguishes interfering alternatives from just plain odds like with dice.
Christodoulou Marios: That since a very good summary of everything I will talk about a modern parlance gravity media to tangle meant would see to acquire a contest gravitational field and.
Christodoulou Marios: Then travel from realizing such an experiment is the coherence, environment, which implies that the outcomes of measurements on the probe probe will be described by probabilistic nature.
Christodoulou Marios: 63 years later, this is roughly still the state of affairs just that we may realistically hope to see this experiment done within a generation which could not have been said in 1957.
Christodoulou Marios: So with regards to the experimental status, this is and what is the main difficulty, this is the situation is to go Harris, the main difficulty.
Christodoulou Marios: Not only, but this is really that difficult thing.
Christodoulou Marios: And with respect to theory where's the.
Christodoulou Marios: here to what degree, is this an accurate statement or not.
Christodoulou Marios: Alright, so.
Christodoulou Marios: This is an animation that they took from this magazine, which is not working here my iPad but you should be able to see it on the slides.
Christodoulou Marios: i'm going to the overview of what's going on experimental.
Christodoulou Marios: And why there is excitement around.
Christodoulou Marios: The possibility to sequential grabbing the table to experiment and what is my understanding from having discussed with people that actually understand these things.
Christodoulou Marios: On what is justified and what is not justified.
Christodoulou Marios: So.
Christodoulou Marios: To give you some history, the song maybe we can say that they started with these efforts by zeilinger and aren't.
Christodoulou Marios: Excuse me here this paper, where they are so interference patterns, by passing.
Christodoulou Marios: project called listings back tubers from great things.
Christodoulou Marios: And within 20 years let's say they went up for orders of magnitude to 10 to the minus 20 kilos this would be the most efficient way to create a separation, with just one of the main things need.
Christodoulou Marios: To create a microscopic preposition.
Christodoulou Marios: But apparently This cannot, they cannot push it very much because there is the issue that, in order to proceed to fear as as you increase the mass, you have to put the screen further away.
Christodoulou Marios: And to to go to scales, where it becomes interesting, you will need to have the meters, and this will be free for so you need to dig a hole of hundred meters and let the things fall into the experiment there, which is just impractical.
Christodoulou Marios: That is at least.
Christodoulou Marios: What everything i'm telling you is mainly coming from Marcus a discussion with microsoft's been mayor and his team, who is the director here in the very good experimentalists.
Christodoulou Marios: Now.
Christodoulou Marios: There is another type of techniques which is based on quantum levitation and optical cooling where they levitate particles now they're at nanoparticles and then with lasers, they can extract energy and put them in the ground state.
Christodoulou Marios: Much of the excitement's is around these developments, because they've already been at 10 to the minus 18 which is orders of magnitude above the previous technique and there are claims that this, there will be rapid progress and even within a couple of years, it can go up by.
Christodoulou Marios: Six orders of magnitude.
Christodoulou Marios: yeah these are two papers that have made some noise lately, so I mean don't ask me the details of what's going on, but this thing here is the laser that is pushing the particle up and keeping it there.
Christodoulou Marios: And levitating it and this other eight lasers, which I think that's why you see the reflection that do measurement next do the cooling and then also the measurements to see.
Christodoulou Marios: They mainly do X and T measurements, to see that you said to date there as positioning momentum to see that the Heisenberg uncertainty saturated and from this, then they can.
Christodoulou Marios: They can do the so called sidebars measurements, from where they can expect the temperature in DC that is close to absolute zero so in a sense, it's still classical you what they can infer that it must be in its ground state, but there is no measure of currents, in that sense.
Christodoulou Marios: All right.
Christodoulou Marios: That is one side of the story, the quantum story, then, on the other side of the story, so the experiments, I talked about both of the pictures they gave those are done in Vienna, and also in Vienna, there is this.
Christodoulou Marios: Other side of the story, which is procedural gravity measurements.
Christodoulou Marios: Now, what is being done here is trying to measure the gravitational field of smaller and smaller masses the the record is from paper.
Christodoulou Marios: Which is between my it's the measurement of the gravitational field of a mass lady said 10 to the minus five kilos it's this mass here it's a passionate pendulum.
Christodoulou Marios: That they modulate and then they can extract.
Christodoulou Marios: From that the signal of the gravitational attraction then we'll look back and forth and.
Christodoulou Marios: This thing is.
Christodoulou Marios: torsion or pendulum This is just.
Christodoulou Marios: A piece of metal to the prudential screen that electromagnetic interaction, which they move to take a foot.
Abhay Vasant Ashtekar: In this case, just measuring the acceleration to drive again, not the type of forces I begin.
Abhay Vasant Ashtekar: particles like that right.
Yes.
Abhay Vasant Ashtekar: Yes.
Abhay Vasant Ashtekar: Yes, yes.
Christodoulou Marios: they're not measuring.
degrading.
Over.
Christodoulou Marios: This is really newtonian force measured.
yell.
Christodoulou Marios: At them I don't I don't think this type they're even thinking of going to send think took to measure Cambridge.
Christodoulou Marios: Now, where they put these photos because there's one question somewhere to be skeptical about what I was saying that the next slide that they're claiming that there's gonna be a lot of improvement, and you know one question is why the soon.
Christodoulou Marios: Basically, because it's just the beginning and now they're getting attention and more funding and resources.
Christodoulou Marios: This a big part of that comes down to simple engineering tasks like doing precision engineering that they have a lab here, creating down to item precision of things, but there's also simply the location, so this experiment, they did it here in Vienna.
Christodoulou Marios: The problem that they were picking up the gravity of the trump just so happens that the term that is passing.
Christodoulou Marios: Like 200 meters from here would give exactly the same feet as passing every five minutes.
Christodoulou Marios: Was destroying all their signal and they were only doing measurement between two and six, when it was not run so now they've given them a sport in this channel where.
Christodoulou Marios: The European Space agency's also doing some experiments with a domino off and just from the fact that they move it and purposes, this.
Christodoulou Marios: it's you see that this really just the box and they got directly three orders of magnitude just because the noise went away without even.
Christodoulou Marios: Improvement of the setup and it's going to be the same for the quantum stuff they will they're trying to also put them in the panel, so there are six pairs of mechanism to get for free for the location.
Christodoulou Marios: So this explains a bit to the hype and the possible excitement that you might hear in the coming years that basically now what's going on is on the quantum side that what I said in the beginning, but the quantum side but putting the ground state and microscopic creatures matter.
Christodoulou Marios: Where now here to manage the two kilos the precision gravity measurements are here and they're claiming that within a few years, we will be here to the minus plus or minus nine and by the end of the decade, maybe we get the numbers.
Christodoulou Marios: Right so that's why it's exciting and it is.
Christodoulou Marios: But there is.
Christodoulou Marios: Just to be clear and they think in this paper marquesas very honest about the situation.
Christodoulou Marios: This is, you know, since the end of it, the big challenges are actually to create a macroscopic preposition which they don't really know they're thinking about it, how they're going to do it even that double sleep type doesn't work.
Christodoulou Marios: Of course, the keep the coherence long enough.
Christodoulou Marios: And then you have to think of an experiment that has both.
Christodoulou Marios: Does both you can both have a quantum matter that they sent me from rotation, that you can keep the coherence along and you can do precision very the measurements.
Christodoulou Marios: And this is completely open really there's ideas coming every week about what to do and what both and experience it on the theoretical side.
Christodoulou Marios: What is interesting for us traditions that there is there is experimental races will definitely continue, and there is a lot of momentum it say.
Christodoulou Marios: On the other side, there is, you know the horizon, maybe 20 years, who knows, so there is a part of the race of thinking of smarter measurements So what exactly do we want to measure.
Christodoulou Marios: Is there a smarter experiment to do.
Christodoulou Marios: All right now I will.
Christodoulou Marios: confuse you a bit because i've been talking about the traps and I will change to a different setup which, however, is the same physics so rather than having you know what I was talking before you would have potentials.
Christodoulou Marios: let's say harmonic potentials where you would trap away function, and this would be your mass.
Christodoulou Marios: And these two would interact and this would create an gravitation early through some type of interaction that would call like.
Christodoulou Marios: write it from all right.
Christodoulou Marios: Sorry, this would be a small team.
Christodoulou Marios: But an equivalent, at least, it seems that the equivalent people.
Christodoulou Marios: saved 100 shown it.
Christodoulou Marios: Another way to think of gravity mated the document would just conceptually much simpler.
Christodoulou Marios: He says, for those this is based on this paper, the setup was proposed in this paper, the setup with a traps was proposed on this paper.
Christodoulou Marios: And this one is with my Center which is completely in Principle number.
Christodoulou Marios: So this is the end V centers where what you do is that you imagine you have two masses.
Christodoulou Marios: In which you embed the spin degree of freedom, a single speaker freedom.
Christodoulou Marios: they're talking specifically about energy centers which are used to quantum computing to create cubits.
Christodoulou Marios: You manipulate the spin you said it in superposition in up and down let's say.
Christodoulou Marios: Initially it's a non untangled state.
Christodoulou Marios: You prepare it in a non untangle state set it up and down and.
Christodoulou Marios: Then you pass it through a reversible stern Gary like type of parameters and, at the end you do measurements on the speeds.
Christodoulou Marios: So that to myself that in the past position by manipulating their.
Christodoulou Marios: spin through magnetic field.
Christodoulou Marios: There initially load the town called the, you have the distance D amp T.
Christodoulou Marios: i'm putting just a branch of close the post here.
Christodoulou Marios: Because I will give some formulas afterwards we're enabling the gravity in all other branch just for simplicity, then we will say much more general division of what's going on here.
Christodoulou Marios: The idea was to leave them to freefall.
Christodoulou Marios: And then you'd measurements of the screens if the speeds become entangled I mean theater of interaction must be able to query quantum information.
Christodoulou Marios: The mediator, is a gravitational field, and does it cannot be class questions, so this is basically the agreement that appeared in these two papers.
Christodoulou Marios: Huge debate.
Christodoulou Marios: ensued into a lot of development and many new ideas on how to do this, both on the feasibility side Now I will turn to the conceptual part, the more theoretical part.
Christodoulou Marios: I should say this is again, this is a very select the.
Christodoulou Marios: Small selection of the literature this papers, I said at 400 times each now so.
Christodoulou Marios: Yes, this is mainly the the references that they.
Christodoulou Marios: more interested in.
Christodoulou Marios: This a bit more in yes it's again explaining them I am again explaining them the phenomenon.
Christodoulou Marios: What happens is that you start non in a separate apple state.
Christodoulou Marios: you end up in a tangled state the simplest way to see this is imagine that you neglect the gravitational attraction in all branches, but this one, where they are closest, then you will get a face.
Christodoulou Marios: And everything like that the phases here because they're much smaller than this one now if this face is not zero then it's non zero entanglement.
Christodoulou Marios: There is a type of protection, you went from say purple to entangled state.
Christodoulou Marios: And then that's something must have mediated least entanglement there's nothing that here you've made sure it's not the electromagnetic field, so it must have been the gravitational field, and thus it must be carrying quantum information and last name of the class.
Christodoulou Marios: That is their story, they are, and so their argument goes.
Christodoulou Marios: Right now, in terms of how this was described.
Christodoulou Marios: You know from gravity, they were initially people were just using basically the the neutrons formula we learned in high school.
Christodoulou Marios: For the gravitational energy which you plug in in the face times time developed H bar and this gives you the quantum face.
Christodoulou Marios: These formulas are just used to determine what are the parameters you're going to need master time and D, initially in the experimental proposals and then assuming a local interaction.
Christodoulou Marios: On top you can make this argument that.
Christodoulou Marios: The gravitational field cannot be classical.
Christodoulou Marios: Now this created huge confusion.
Christodoulou Marios: And discussion on what exactly is there to be claimed if we see this phenomenon i'll give you a few points of view.
Christodoulou Marios: First of all, there is the side, where.
Christodoulou Marios: People say there is this has nothing to do with quantum gravity it's agnostic to the quantum of classical nature of the two degrees of freedom.
Christodoulou Marios: does not involve two degrees of freedom, this is, this was a Comet that appeared in this two papers that were publishing period, it was a pure comment period very soon after this is a much more detailed analysis.
Christodoulou Marios: In.
Christodoulou Marios: claiming to be non paratrooper that but not really.
Christodoulou Marios: Where essentially what's been gone is that they do the usual.
Christodoulou Marios: splitting of the gravitational field into a Colombian part of transfers part.
Christodoulou Marios: And then they neglect the transfer this say Lucas just a Columbia part of is not decrease the freedom equals i'm doing a very unfair summary it's a big paper, but this will be familiar for my name is Melissa too many of you.
Christodoulou Marios: There is.
Christodoulou Marios: on the opposite side, there is a claim that it implies detection of visual gravity.
Christodoulou Marios: Which is.
Christodoulou Marios: Very exaggerated, in my opinion it is problematic because two of the people.
Christodoulou Marios: suggesting this mazumdar and both are two are the two main office of.
Christodoulou Marios: Of of the whole idea.
Christodoulou Marios: Of the paper that proposed the setup that I just explained, which also has more detailed feasibility study and the better entanglement witness it's more detail.
Christodoulou Marios: Now, their claims are based on doing the analysis in the quantum field theory.
Christodoulou Marios: In a canonical setting in the hamiltonian setting and showing that you can get the the description of the phenomenon by expressing the newtonian potential as visual gravitas essentially.
Christodoulou Marios: identity as a claim is, in my opinion, very exaggerated, because this doesn't show anything that point is that you can also describe the phenomenon without using that, which is what we will see.
Christodoulou Marios: So these are the two extremes, for me, nothing to do with quantum gravity vitriol gravity payments.
Christodoulou Marios: Of course the question would be a bit, first of all, you see gravitas before you think about future gravitas and done or this middle ground there is.
Christodoulou Marios: I don't know if I should be calling them to points of view, maybe to be done, fair, because there is another level, so in the authors, but there is this let's say isolation between what to say.
Christodoulou Marios: There is a diagnostic statement that.
Christodoulou Marios: Seeing induced entanglement would imply that quantum formations carried by the non relative part whatever you want to mean by that.
Christodoulou Marios: which are mainly mainly coming from these papers here.
Christodoulou Marios: And Bob file the, which is the Co authors here.
Christodoulou Marios: has recently put out another paper, two years later, where he's getting a bit from the more careful statements that were being made here.
Christodoulou Marios: And they're saying you're trying to untangle mud mud is you doesn't play any the existence of the gravity there.
Christodoulou Marios: To to save these they're using smart argument that's coming from this papers which, if I have time and you're interested, they could go a bit into but it's it's it's a bit of a convoluted story.
Christodoulou Marios: And one issues that everybody's doing them in their own firm, and this is seen.
Christodoulou Marios: In kirsty in Cap space same language essentially using the client Gordon.
Christodoulou Marios: Inner product properties.
Christodoulou Marios: This is seen.
Christodoulou Marios: As matrix for management which ones are more contact information, this one is more to 50 years and current state and, yes, there is this lively debate, which I heard that that's going to put out a paper today or yesterday which I haven't read criticizing these papers that are wrong.
Christodoulou Marios: All right now the middle ground that I have been.
Christodoulou Marios: Settling.
Christodoulou Marios: To personally is that.
Christodoulou Marios: What we might say is that is affected texts, a microscopic proposition of space time essentially the existence of.
Christodoulou Marios: Two positions of some classical states in the state space of.
Christodoulou Marios: The theory that describes this low energy regime.
Christodoulou Marios: And I would like to qualify that even further, but should do this first cover some more crowd.
Christodoulou Marios: So now, I will talk about this latest paper and take you through the calculation is nothing fancy and complicated and discuss a bit at the end what our conclusions.
Christodoulou Marios: Are the me read the the the the physical intuition conclusion.
Christodoulou Marios: So the physical picture arising from the analysis that information travels in the quantum superposition of field with France.
Christodoulou Marios: And mechanism that propagates the quantum information with the speed of light is a quantum superposition of microscopically this thing then i'm going to feel comfortable.
Abhay Vasant Ashtekar: Getting alicia What do you mean by field vacations in.
Christodoulou Marios: In gravity and so I will spend the next four slides making more clear.
Christodoulou Marios: I mean, this is just the words.
Christodoulou Marios: Right now, this is just physical to.
Christodoulou Marios: Their their technical conclusion is not this.
Christodoulou Marios: But I hope for this intuition, we can discuss it, too, because actually.
Christodoulou Marios: 80% sure I put them dish so all right, this is a setup.
Christodoulou Marios: We imagine there is a partition function, this is heuristics on up to this.
Christodoulou Marios: So this is really just say imagine there is a path integral where these are they.
Christodoulou Marios: The paths, so you remember, I should have put a figure here i'm referring referring always to.
Christodoulou Marios: A situation like these, although the formula is is applicable to arbitrary paths and arbitrary number of particles, so the X is paths of particles point particles, we will take.
Christodoulou Marios: In a bit in particular.
Christodoulou Marios: What here, then the practical some confusion i'm sorry, so this is the paths degrees of freedom, and this is a field degree of freedom.
Christodoulou Marios: Now the action is and.
Christodoulou Marios: Then ethical variables are the paths labeled by a for the number of particles and F is the field by field, what I mean, in particular, is for electron electromagnetism the vector potential and for leaner is gravity the metric perturbation we just put it as F, because we took those places.
Christodoulou Marios: in one go because they're very similar.
Christodoulou Marios: All right, and then there is the mass there is a magnetic field, there is the spin configurations.
Christodoulou Marios: Where the spin configurations are.
Christodoulou Marios: The tensor product over the individual spins that are embedded in these particles.
Christodoulou Marios: All right.
Christodoulou Marios: We imagine there are some semi classical states that we will use to fold this partition function this path integral devolution an operator that gives the evolution from here to here would be.
Christodoulou Marios: given by would be over this form, because this is simply because the spins do not.
Christodoulou Marios: Change along the path So these are somehow external degrees of freedom manipulated by these external feet.
Christodoulou Marios: So your evolution of PR we split in this form.
Christodoulou Marios: Then we take a.
Christodoulou Marios: tool.
Christodoulou Marios: Simple approximations with take the field to be on Shell.
Christodoulou Marios: So the field now is on shed in the sense that it satisfies.
Christodoulou Marios: The field equations.
Christodoulou Marios: For particles with trajectories.
Christodoulou Marios: X.
Christodoulou Marios: And then the integral over the paths can be performed by simply assuming that their paths are nearly orthogonal okay.
Christodoulou Marios: There is, this is really just putting things together there's no real calculation that the reason we do this is because we want to show.
Christodoulou Marios: That these phases that are creating the entanglement that people are talking about our own selections right, so you the final state is.
Christodoulou Marios: The evolution of either active or the initial state and it's simple a few simple steps show you that the final state is going to be proportional we don't care about the normalization because we want the phases, to the final state of.
Christodoulou Marios: This is the field.
Christodoulou Marios: And the paths this side it's more site.
Christodoulou Marios: And the speeds are factoring out in terms of product, but they have these phases, which, if they're not.
Christodoulou Marios: which can give you a nonzero entanglement depending on what they are, where the phases are defined as these contracts.
Christodoulou Marios: And this is.
Christodoulou Marios: The point.
Christodoulou Marios: That these phases let's create entanglement our own selections.
Christodoulou Marios: Now.
Christodoulou Marios: All right, what these men see particular than you, you can check it explicitly which we did is that it means they're going to be gauge of rem.
Christodoulou Marios: and
Abhay Vasant Ashtekar: What is a field i'm sorry, it is just an atonement field grab the i'm confused about what the framework is, are we talking about sheila as being produced by oh if you're just talking right now okay.
Christodoulou Marios: Yes, yes i'm doing things to be done.
Abhay Vasant Ashtekar: But.
Abhay Vasant Ashtekar: paradigm is that there's a flag space and flash space time and then there is a perturbation on it.
Abhay Vasant Ashtekar: Yes, produced only by this by these particles.
Abhay Vasant Ashtekar: Yes, what is particles.
Christodoulou Marios: Yes, yes, the setup is.
Christodoulou Marios: Linares gravity first order.
Christodoulou Marios: Where this is across the space.
Christodoulou Marios: Of a domino, and this is a perturbation which will be sourced by the trajectory of the parks.
Abhay Vasant Ashtekar: So you're ignoring earth's gravitational field.
Christodoulou Marios: Excuse me.
Abhay Vasant Ashtekar: But yet ignoring earth's gravitational field in which this part, yes, there is no external field it's all is that.
Christodoulou Marios: There is also ignoring the back reaction.
Christodoulou Marios: Yes, there is, there is an external magnetic field.
Christodoulou Marios: Which is manipulating the spins but we're ignoring the back reaction of the spins end of the magnetic field on the field and where are so ignoring the reaction of the field of hulu on the trajectories of the park.
Abhay Vasant Ashtekar: grows right.
Yes.
Abhay Vasant Ashtekar: Okay.
Christodoulou Marios: The point being that this is enough to get the Lawrence engage in violent expression of the subjects.
Abhay Vasant Ashtekar: don't control like and what i'm confused about is it, why is it.
Abhay Vasant Ashtekar: Okay, please go maybe we should respond.
Christodoulou Marios: No, no, please, please.
Abhay Vasant Ashtekar: i'm confused about.
Abhay Vasant Ashtekar: One can do things that are you know when can do calculations and it's a good motivation to do calculations, because we can finish the calculation and when was the last time that.
Abhay Vasant Ashtekar: But I think affordable for us, for the rest of us, we want to know what is the justification of this approximation, why do we think that those effects are negligible.
Abhay Vasant Ashtekar: And, and my thing is that in action lab if you are going to perform the experiment, then of course they'll be earth's gravitational field, but more than others, Guy will feel there'll be posted on the fence.
Abhay Vasant Ashtekar: And the new new coming from the poster donnie and effect, why is that going to be negligible compared to you know the final answer that i'm getting these are the kinds of questions, I mean you can consider the ideal I systems, but.
Christodoulou Marios: Yes.
Christodoulou Marios: Yes, I think we're not doing them because we expect them, let them complete negligible by would be nice if I should but I agree okay.
Christodoulou Marios: So, so the polling.
Abhay Vasant Ashtekar: Looking at idealized system and just seeing what the calculation does and i'm perfectly happy with that.
Christodoulou Marios: Yes.
Ivan Agullo: I was confused with something you just said, you said that you are neglecting the map reaction of hulu on the directory of the particles.
Ivan Agullo: In the end of us because it's not the game here that the two particles interact via HBO so the.
Christodoulou Marios: Lead so that is a very good point I think that's a big part of how this debate can be resolved.
Christodoulou Marios: Let me go to the next slide and then we can come back to this yes so just so that they can define things precise so here, this is the action of Linares gravity.
Christodoulou Marios: The full action you get that the first order.
Christodoulou Marios: If you expand to actually hit production, this is written lauren stage.
Christodoulou Marios: The questions of motion that i'm sure you're all familiar, all are familiar with.
Christodoulou Marios: And then you plug in the solution you use the questions of motion back into the action and you get this on selection, which is not surprisingly, this term, but there is a one over for this one house factor which is important to get them, then you turn a limit correct.
Christodoulou Marios: Otherwise you get twice.
Christodoulou Marios: The.
Christodoulou Marios: neutrons gravity you get twice as big things.
Christodoulou Marios: Now the team he knew their energy sensor is given by.
Christodoulou Marios: a collection of point park to god's.
Christodoulou Marios: You see, the deltas that they're forcing.
Christodoulou Marios: The Court ministry on these paths.
Christodoulou Marios: and
Christodoulou Marios: We will know is simply it's the favelas this.
Christodoulou Marios: And the Lawrence fact.
Christodoulou Marios: Alright, so this is entertainment content sort of point particles or jacket and a source.
Christodoulou Marios: Now you can see here what I meant that these acts of tr God given here.
Christodoulou Marios: You just determined them from the beginning for all time and then you get the feet.
Christodoulou Marios: For that now you have an exact fit solution for these two minutes.
Christodoulou Marios: All right, this is the exact solution of the.
Christodoulou Marios: Question so motion of the literacy of these questions.
Christodoulou Marios: These are the Essentially, these are the analog the gravitational Allah log to the linear weaker solutions if you have heard of them of electromagnetism.
Christodoulou Marios: which are very known they're also in advanced courses of electromagnetism.
Christodoulou Marios: And it's the solutions that people use to cloth diaper radiation, for instance animations but they show us in class.
Christodoulou Marios: Yes, again, this is an exact solution and the quantities in here this distances are impacted quantities they depend on the type of time which is implicitly defined by this condition here.
Christodoulou Marios: And then the actual action you just plug this solution back to your action, and you can write a an exact expression within Linares gravity, I mean it's exactly it's exactly electromagnetism.
Christodoulou Marios: Where again, the time is defined the Priestly the title tends to mean by this condition.
Christodoulou Marios: What that does just to remind you is that, did you ask for the value of the field that some eggs empty.
Christodoulou Marios: their entire time we.
Christodoulou Marios: produced by some particle that is doing some trajectory then.
Christodoulou Marios: It will trace the light con and find the detective time to be on that trajectory and that's where to click here so.
Christodoulou Marios: This is the Lawrence advantage revised version for the observer balls we conclude that entanglement arises due to a local interaction mediated by physical degrees of freedom oops this type of here sorry.
Christodoulou Marios: and not to come to your question event.
Christodoulou Marios: There is i'm saying that this is more than sufficient is because when you see, this is a full thing this is lauren surviving scheduled right and it has.
Christodoulou Marios: Corrections relativistic corrections have two kinds of the corrections to the mass and to the momentum so the sourcing of the field by momentum and by mass it, so this is what I mean by this is that this is not only T 00 it has all the energy.
Christodoulou Marios: Momentum cancer components.
Christodoulou Marios: In it, and then there's also a little dash.
Christodoulou Marios: All right.
Christodoulou Marios: Now you can go backwards and say Okay, how do I recover this formula which was this newtonian face think that we find in this papers.
Christodoulou Marios: Well, first, you can take a slow moving approximation, which is simply that the velocities much less and see and you get I think it's plus O V C squared corrections, you can see in the paper we have it.
Christodoulou Marios: And this is basically it looks like the causal version of newton's law when you're right, it is an action, this still has rehabilitation in it.
Christodoulou Marios: All right, and then you can.
Christodoulou Marios: also take an independent approximation, which we can call near field, which is when you neglect the Foundation effects in the vicinity of where you're taking where you're doing the experiment you just put them instantaneous the coordinate pain.
Christodoulou Marios: When you take both approximations you get the than your turn and limit and you also assumes that this is this or this, because this is what they're doing this from some static phase here.
Christodoulou Marios: That gives you the dominant contribution if you also do that, then you get back this formula so.
Christodoulou Marios: To answer your question Yvonne it does not seem so does not seem that you need to consider the reaction of the field on the trajectory of the particles, because this is more than sufficient to give you.
Christodoulou Marios: It obviously gives the correct limit.
Christodoulou Marios: It already includes.
Christodoulou Marios: sedation and other kinds of relativistic effects and.
Christodoulou Marios: This is simply not what you would detect in the expert you, even if there is a correction, the particles it's the wrong petition to think about what you're detecting is that the particles go a bit closer because of the gravitational attraction.
Christodoulou Marios: That is completely negligible sorry I didn't do don't have the calculation, but we have this in the previous paper with Carl it's easy to write down it's like terms of this magnitude below, so the Judas divination.
Christodoulou Marios: And this is where the confusion comes from to that, if this is not for detecting then, how is our the gravitational degrees of freedom involved in the experiment.
Abhay Vasant Ashtekar: You want.
Christodoulou Marios: I just I just have the last slide maybe I just read through it.
Ivan Agullo: Please, and we go.
All right.
Christodoulou Marios: Yes, I wanted to explain just one last thing that in this paper we also show that there is a way to make this observable right which is that what you do is that you shoot the particles.
Christodoulou Marios: so fast through this so you do an undo this wasn't so fast that the light cons look like this.
Christodoulou Marios: So what is the more precise way to say that the D E is less than city.
Christodoulou Marios: way around.
Christodoulou Marios: and
Christodoulou Marios: Which means that they will they while they're in superposition.
Christodoulou Marios: They have not yet interrupt the gravitational, which means that you will get zero and Panda.
Christodoulou Marios: And then just simple derivation in the paper.
Christodoulou Marios: So this gives you the observable effect them and for gravity has to be completed in physical, fortunately, but it could be done for electromagnetism.
Christodoulou Marios: Which is still interesting because all these arguments and counter arguments they also apply to electromagnetism this will make the point that.
Christodoulou Marios: Look, this is not instantaneous I think it takes some time to build that these phases take some time to build up because there is with edition here all right.
Christodoulou Marios: And discussion.
Christodoulou Marios: quickly go through the slide there have been claimed that the gravity disentangled minute similar experiments can provide fear, independent and big evidence.
Christodoulou Marios: The gravitational field isn't with classical this heavily relies on electricity rents low calibrated operations in classical communication.
Christodoulou Marios: Of quantum information which may be too strong statement I given two papers, where this is claimed personally were looking into this I didn't i'm not sure.
Christodoulou Marios: I do not think you can make the theory independent statement, it seems to me that the importance of the experiments is.
Christodoulou Marios: Clear, if you take linear as quantum gravity and you say that look if you're you're thinking, the following sense is there a feature of this theory.
Christodoulou Marios: That is quantum and it's being witnessed by this experiment, for instance, take the form of an apple it's also predictable yeah that's kind of gravity does it see any quantum feature of the theory, no.
Christodoulou Marios: How about this phenomenon, I think, yes, in the sense that, if you do not have some prepositions have some classical states in the state space.
Christodoulou Marios: You would not.
Christodoulou Marios: The effect would not take place.
Christodoulou Marios: Would you know the lot.
Christodoulou Marios: Though it just saying that distinguishes it from let's say some classical gravity or other theories that.
Christodoulou Marios: treat the gravitational effect as class.
Christodoulou Marios: There remains confusion, what exactly is going on with stuff from to fit this the papers I mentioned, this is, in particular with respect to the role of ideation the minimum of two degrees of freedom.
Christodoulou Marios: an experiment, where all sorts of different is witness would be much more powerful because locality need not be assumed, but this is difficult.
Christodoulou Marios: and
Christodoulou Marios: I wanted to mention briefly this work, which, fortunately, they have to talk about this is a completely different protocol, which does not suffer from these issues, which is based on witnessing the negotiated the production on in quantum gases.
Christodoulou Marios: it's completely open to think of alternative protocols techniques and smarter measurements to think of other tests, like this one, for instance.
Christodoulou Marios: And yes, this is things I talked about in the last purchase, which is about the description of time, the excuse me, that its greatness of time I don't have much to report on this front So yes.
carlos beltrán: slides.
carlos beltrán: And because you said that the trajectories of the particles are all to go now but I don't know why I mean, I think the states are going i'm not a trajectory but maybe i'm wrong.
Christodoulou Marios: I mean, if you think of them as wave pockets.
Christodoulou Marios: Somehow is week functions website l say our.
Christodoulou Marios: Side side are almost zero so they overlap of this girl oceans this.
carlos beltrán: Statement server space not it's not exactly the trajectories of the park okay.
Yes.
Abhay Vasant Ashtekar: So let me just ask a couple of quizzes Well, first of all, you, and if you go to the previous slide at the previous slide maybe 16.
Abhay Vasant Ashtekar: yeah So here we see that you are as of last formula area or down as a seat to the fourth there so on right.
Abhay Vasant Ashtekar: So you would imagine that I am just confused about.
Abhay Vasant Ashtekar: Sports at all if you can newtonian limit and such thing I would I just thought that, therefore, in the middle, in the middle just get zero answer but that's not the case.
Christodoulou Marios: So.
Christodoulou Marios: So this is a limit take this formula that is here at the now what you do is that you expand in powers of the receipt.
Abhay Vasant Ashtekar: yeah, but I think you just get to but yeah Okay, but still, it is see the the.
Abhay Vasant Ashtekar: morning that.
Christodoulou Marios: knows you lose see from here with cancels out.
Christodoulou Marios: This is, this is what you get.
Abhay Vasant Ashtekar: I do this is C squared is my question exactly.
Abhay Vasant Ashtekar: You see, to the fourth their.
Christodoulou Marios: message to their paper because they just don't remember this behind.
Christodoulou Marios: what's going on is this that.
Christodoulou Marios: Sorry, by the pen is not working now just above a question 10.
Christodoulou Marios: This.
Christodoulou Marios: V times we term, which is in the Question nine is equal to see fourth.
Abhay Vasant Ashtekar: is going to be C squared, so why do you see for.
Christodoulou Marios: sure.
Abhay Vasant Ashtekar: yeah my back and figure was I thought should be C squared Therefore I.
Abhay Vasant Ashtekar: Thought okay i'll go back and look at it, thank you.
Christodoulou Marios: Yes, in the supplementary material just to get you will have the derivation really step by step, starting from the action.
Christodoulou Marios: doing everything but I don't remember, sir.
Christodoulou Marios: Sir.
Hal Haggard: In your appendix isn't it right there.
Hal Haggard: That your definition of the capital, the new new it goes like B squared no.
Hal Haggard: Yes.
Christodoulou Marios: See here, yes it's from.
Christodoulou Marios: here.
Abhay Vasant Ashtekar: it's Friday.
Abhay Vasant Ashtekar: Other right capital B is not the same as me.
Christodoulou Marios: Yes, yes.
Abhay Vasant Ashtekar: I saw the capital V was just okay.
Christodoulou Marios: So tell me a.
Hal Haggard: Little V squared and then he had capital D squared so that gives us yes.
Abhay Vasant Ashtekar: That is fine, because capital I capital, it was around all cities.
Christodoulou Marios: Yes, that's where it's yes it's a bad choice of notation so this capital V has to Vanessa it's the stuck here, so my question is TIM yes.
Abhay Vasant Ashtekar: Okay, so, then my second question is, why is it.
Abhay Vasant Ashtekar: I mean if in fact they already controversy in electromagnetism where you think the shoes are clear cut because no, you know don't have to worry about superposition of space time or anything or anything.
Abhay Vasant Ashtekar: Can you tell us why there is controversy in the electromagnetism where you know.
Abhay Vasant Ashtekar: relationship.
Christodoulou Marios: Because.
Christodoulou Marios: Essentially, people are saying.
Christodoulou Marios: There is confusion about the immediate or what is going on with immediate.
Christodoulou Marios: What you can say is that look, this is a Colombian tax, we know that did you take a quantum mechanics your room you put the one over our interaction and the hamiltonian as you're going to get entangled, why are you making all this fuss about having sense, so if you're thinking.
Christodoulou Marios: you're thinking about the electromagnet this would be my language, the position of.
Christodoulou Marios: semi classical configurations of the feet of the electromagnetic field.
Christodoulou Marios: However.
Christodoulou Marios: It is not true right that this instantaneous interaction is just an approximation.
Christodoulou Marios: Now, if what is really going on is.
Christodoulou Marios: But there is a local interaction that is mediating.
Christodoulou Marios: So the introduction is mediated locally by some, something that is in the middle there's a third system, you know just the masses and they miss the time is traction there is a third system that corresponds to that direction, then.
Christodoulou Marios: That media or that gravitational link that fame I was talking about, so that bus, if you want it needs to be able to query quantum information.
Christodoulou Marios: And that cannot happen if it's a classical that's where all the story starts from.
Christodoulou Marios: I say said this type of argument or investigating it i'm not sure how much water it holds.
Christodoulou Marios: To this moment, but I think there is something interesting there to understand, so that the confusion is basically that this seems to have nothing to do the radiation.
Christodoulou Marios: Yes, it has seems to have to do with the red non relative part but.
Christodoulou Marios: If you do the usual thing of splitting.
Christodoulou Marios: Taking out the transfers parts electromagnetism or the transfers tasteless that you're putting all the degrees of freedom in there, but then you're going to neglect them, because this is what you would do you understand the radiation in the far field.
Christodoulou Marios: So this step seems to not be appropriate to explain the how the information is mediated.
Christodoulou Marios: Yes, and what is the correct way to say things I don't know.
Abhay Vasant Ashtekar: Okay, thank you, I mean I.
Christodoulou Marios: know no please.
Abhay Vasant Ashtekar: I know I mean, I think that it might much easier to is much easier to look at electromagnetism and then.
Abhay Vasant Ashtekar: I mean it just would have been correct and and to see to what extent it is true that in quantum electrodynamics the color of interaction, he is really.
Abhay Vasant Ashtekar: classic right.
Abhay Vasant Ashtekar: And I think that it is not cool of interaction is as customers.
Christodoulou Marios: Okay.
Christodoulou Marios: That is very inconvenient book here from.
Christodoulou Marios: All these papers do treat the electronic design also.
Abhay Vasant Ashtekar: You mentioned that I was going to fill up that there are a lot of controversies they're also used to it okay and i'm happy to understand what the.
Abhay Vasant Ashtekar: What the debate is a lot.
Christodoulou Marios: That it would take another seminar maybe I mean i'm bad at explaining this I would encourage you to have a look at the book volts paper, the latest one yeah.
Christodoulou Marios: So we haven't really put the two things together they're saying what we're saying is related to this stuff we're saying it must be related, but I think.
Christodoulou Marios: Nobody has figured it out we're in discussions, yes, I expect that to continue.
Abhay Vasant Ashtekar: Thank you.
Ivan Agullo: But what one question related to this, I mean the two particles are nearby So how do you separate the radiative and they go on the part of of any field if it's you know my understanding is that there is some DVD unless you go to the to the radio, the freedom right really far away so.
Christodoulou Marios: that's what I think true and instead of trying to make sense of that which is what some people did, and you get this.
Christodoulou Marios: other places, this is nothing to do with there's no degrees of freedom artificial graphs to do both things I just tried to do it in the current language, where you do not you do the path into crab you never have to split.
Abhay Vasant Ashtekar: And here is the four layers.
Abhay Vasant Ashtekar: That you cannot do the parking ticket splitting.
Christodoulou Marios: Because, yes, you split the minor.
Abhay Vasant Ashtekar: part would not be the major would not be gulshan.
Abhay Vasant Ashtekar: Your district I don't think that part integral did anything beyond what will be done just an ordinary field theory, I mean.
Abhay Vasant Ashtekar: This HBO new etc right, I mean they would not be the major on the space of.
Abhay Vasant Ashtekar: If you include all degrees of freedom, I mean all 10 components H menu, and not just transfer stress less than the interior doesn't convert, as we know, right, I mean.
Abhay Vasant Ashtekar: apart because of the, for example, because the confirm one degree of freedom in age from.
Abhay Vasant Ashtekar: So I think that implicitly in this form of manipulation, there is actually splitting and you're probably are using transfers degrees of freedom without are the major corresponding transfers degrees of freedom.
Christodoulou Marios: And I haven't defined the measure So yes, I agree with it it's completely hurry.
Abhay Vasant Ashtekar: Without saying it right, exactly, so I don't think I think these are normal manipulations right, so it might be a case.
Christodoulou Marios: Yes, yeah I wanted, I wanted to see what I meant to say is that they want to be covariance formula of the phases, but i've not for what could be hidden is you if you.
Christodoulou Marios: Sit down and define them the path of the crowd precisely.
Christodoulou Marios: Yes, I don't have anything on that, but thank you for the comment.
Deepak Vaid: i'm RDS.
Christodoulou Marios: hi.
Deepak Vaid: So I have a, I guess, more than one question the first is like, as has already been mentioned by you and by be electromagnetic case would be the natural stepping stone to the gravitational case right because.
Deepak Vaid: As one might, as we know from looking at these calculations, you get the same result only with G and being replaced by K and you.
Christodoulou Marios: know.
Deepak Vaid: So so.
Deepak Vaid: Are there any plans for performing experiments, such as such experiments with with charged particles.
Christodoulou Marios: Yes, there are they have their own difficulties there which are different from gravity, they have not happened, I have not had a detailed discussion so for why.
Christodoulou Marios: One thing I can tell you is that, on this idea of putting them apart and back together a reversible.
Christodoulou Marios: still get like was.
Christodoulou Marios: reported like a year ago.
Christodoulou Marios: So now, they would have to put to and measured interaction for electrons mean.
Christodoulou Marios: Or what you said is completed through it said here, and as you can see that cannot show where it says, replacing V with small V on with you, and you can the formula for electromagnetism.
Christodoulou Marios: it's completely and.
Christodoulou Marios: I don't know why they haven't done it yet apparently sorts of.
huh.
Deepak Vaid: Okay, and this second thing is that um so if.
Deepak Vaid: There are, there are two aspects right the first aspect is.
Deepak Vaid: Can you generate entanglement.
Deepak Vaid: Between any two systems which are interacting via some sort of one by R squared or some central potential right that's, the first thing and like like you said you, you can do that right in electromagnetism.
Deepak Vaid: Yes, this The second thing is that.
Deepak Vaid: If if one can do that with gravity Does that imply gravity is a.
Deepak Vaid: You know quantum mechanical entity or if.
Christodoulou Marios: That is a claim.
Christodoulou Marios: That is a claim the dysphoria forces you to say that this.
Christodoulou Marios: It cannot be a classical food.
Right.
Deepak Vaid: Now, the thing is that let's say that both of these are our our crew.
Deepak Vaid: Then.
Deepak Vaid: wouldn't the gravitational field be creating entanglement all over the place, you know, for instance, if I if I think about something.
Deepak Vaid: hydrogen energy particles hitting the upper right.
Deepak Vaid: you're drinking shoppers of new ones, or whatever other other kinds of back.
Christodoulou Marios: Then, because there's nothing is going to be in principle in a superposition Everywhere you.
Deepak Vaid: Go because you know I mean you have particles traveling around along different paths.
Deepak Vaid: And i'm not saying of course that those configurations will.
Christodoulou Marios: So I think what you're saying might be answered, so these three papers I mentioned from Bob lower voltage all three of them.
Christodoulou Marios: They study quantum fluctuations and the thing is that you cannot get which path information, unless you can distinguish.
Christodoulou Marios: So unless whatever is your prob can can be the localized sufficiently to distinguish it from vacuum fluctuations, otherwise you cannot get information, so you do not.
Christodoulou Marios: generate entanglement and you'd also get the coherence and this is exactly the type of good I can experiment that has been that have been considered.
Christodoulou Marios: In these papers here I lost my pencil here.
Christodoulou Marios: In this three and this one.
Christodoulou Marios: So it's you know you can just imagine that it's the whole thing classical everywhere, I mean there is.
Christodoulou Marios: soon going to be a limit would get so small, the difference that you cannot religion or the impact.
Christodoulou Marios: And that is something missing from the story is it, by the way, which we're trying to put that into the story to.
Christodoulou Marios: Even sorry the packet if you were.
Deepak Vaid: No, no, no, no, thanks I lost after afterwards.
Christodoulou Marios: Thank you.
Ivan Agullo: So.
Ivan Agullo: What are you having just a conclusion about the main the main point so maybe you can help me to to to understand and so perhaps you can come back to your picture of the light cons.
Ivan Agullo: Right.
Ivan Agullo: So I understood from the beginning that the game, we are playing here is that these two particles are going to interact very.
Ivan Agullo: are very interact gravitationally you know one is going to produce if they are going to interact by the mutual going to be the wrong direction.
Ivan Agullo: And that is going to introduce faces that you can detect later on, but looking at the picture, so there are two things that confused me.
Ivan Agullo: One is that in your calculation particle a never feels the gravitational field of article beat so so, then I don't understand how the whole picture can be realised can can be materialized.
Ivan Agullo: And second this picture tells you that you know, whenever the two one particle be you know, like to party sessions are separated.
Ivan Agullo: You know that is not in Council contact with particle a so so the gravitational interaction doesn't have enough time to reach each other so, then I don't understand a whole, you can have gravitationally in the face.
Christodoulou Marios: Okay, so there was it's it's two parts, the second was my fault, so I was saying that, in this case when the lead concert like that you do not.
Ivan Agullo: Do not get so you need you need, then, you know when to move forward in dental dealer.
Christodoulou Marios: You need them to move slow enough so that the light console you know, like this.
Christodoulou Marios: so that they can actually.
Be.
Christodoulou Marios: You need the trajectories to be in cause of contact.
Christodoulou Marios: To unit this trajectory is to be.
Christodoulou Marios: In the future of.
Christodoulou Marios: At least most of them so.
Christodoulou Marios: Is this clear what I said or am I think.
Ivan Agullo: That that is perfectly.
Christodoulou Marios: All right, good So the first part, I agree that this is this is counterintuitive and it's important so you're saying that do not fit the revelation of each other, because there is no just deviation but it's not, this is not only that.
Ivan Agullo: Is because you are what you call the back reaction back reaction, you were you were saying that you know particle beam doesn't.
Ivan Agullo: that's me yes.
Ivan Agullo: react to the gravitational field.
Christodoulou Marios: Created yes, yes, in this sense that we're not feeling the composition of the thought were putting quantum mechanics right and then quantum mechanics there it's also the phases and that's what we care about, and this is.
Christodoulou Marios: What we show we just do the innovation, starting from the gravity and which we see that.
Christodoulou Marios: Discussion quantum physicists are given in this theory by this expression.
Christodoulou Marios: Right.
Ivan Agullo: Maybe make my point is, why should I integrate that face as the reaction of particle be to the gravitational field of article.
Christodoulou Marios: Because it's a function of of.
Christodoulou Marios: This is.
Christodoulou Marios: given us.
Christodoulou Marios: This.
Christodoulou Marios: that's what I would say that, because these phases are equal to this monster election, which is a function of vision.
Christodoulou Marios: and
Christodoulou Marios: I see you're just sitting there is something.
Ivan Agullo: I mean, I just want to understand.
Christodoulou Marios: It is it is due to the.
Christodoulou Marios: I mean listen to this if it's not just the aggravation of what What did you.
Thank you.
Christodoulou Marios: Maybe that's.
Jorge Pullin: Yes.
But I agree that this.
Christodoulou Marios: I don't know I don't have the sufficient to say there's no greater Chris waters.
Christodoulou Marios: were thinking about.
Suddhasattwa Brahma: So maybe you said this already.
Suddhasattwa Brahma: But just to clarify, so the H menu for you is not just the transfers trace this more right it's like.
Christodoulou Marios: No, this is this is.
Christodoulou Marios: All of us, yes.
Suddhasattwa Brahma: yeah Okay, and then my second question is, what do you call this until action it is essentially just like integrating all.
Suddhasattwa Brahma: This new field right.
Suddhasattwa Brahma: that's.
Christodoulou Marios: More than just.
Suddhasattwa Brahma: Integrating out to to the leading order.
Christodoulou Marios: i'm.
Christodoulou Marios: doing in the previous presenter provider was saying.
Christodoulou Marios: Yes, yeah.
Suddhasattwa Brahma: Because you're using the equation solution.
Suddhasattwa Brahma: For it and then playing it back in radio.
Christodoulou Marios: Yes, yes, yes.
Suddhasattwa Brahma: So then, my question is, I mean if I just think of a to field to scale, a field system or something like this when we integrate out, we say we are integrating all the heavy fields, based on.
Suddhasattwa Brahma: Energy scale which are which we consider right and we say, for me, the scale of what we are interested in is much smaller than the mass of the heavy field, or some some hierarchy like this, then we are allowed to integrate so.
Am I.
Suddhasattwa Brahma: Is there something like that is there some hierarchy of skills which you are implicitly considering him for which you can for which you can think of integrating out this a communion.
Christodoulou Marios: Oh.
Christodoulou Marios: that's a good point then another word that this has been that said in this way.
Christodoulou Marios: In the papers that are there i'm suspecting that this is sort of what's going on, if you take this point of view of understanding, whether you can teach which part information or not with a scale being said by the vacuum fluctuation, but I have not.
Suddhasattwa Brahma: Okay, all right.
Christodoulou Marios: that's.
Suddhasattwa Brahma: A good point so nice to.
Deepak Vaid: Okay, I have one more question good so we're talking about particles, which is nice.
Deepak Vaid: Now, and.
Deepak Vaid: The gravity that you're using here right, I presume, is.
Deepak Vaid: you're assuming make the torsion precondition and so on, right.
Christodoulou Marios: yeah yes okay.
Deepak Vaid: So so.
Deepak Vaid: what one might.
Deepak Vaid: expect or one might think that since you're dealing with the with particles which have spin.
Deepak Vaid: night and Sprint courses spin sources portion in the Baptist and it.
Deepak Vaid: shouldn shouldn't that play a role in these concerts.
Christodoulou Marios: I have not thought of making that seeing whether it's.
Christodoulou Marios: Yes, the answer is yes, it should resource section I agree with you i've not thought about that i've not looked at it.
Christodoulou Marios: We just make a comment that this.
Christodoulou Marios: spin degrees of freedom, I really there to use to be used as handled to move the particles around right.
Christodoulou Marios: and
Christodoulou Marios: Excuse me and they're also used to make measurements on them.
Christodoulou Marios: to witness the entanglement but they're not.
Christodoulou Marios: Really part of their you know of the interaction now i've no idea how to get to that effect that was imagine it's minuscule, but it would be tested on the other direction, three, given that they can do this thing in bed spins is an experiment to see.
Christodoulou Marios: Whether or not i'm not.
iPhone von Wolfgang Martin Wieland: So sorry to jump in.
iPhone von Wolfgang Martin Wieland: On this point, so the the spin marvel use that you're talking about isn't it like this pin of.
iPhone von Wolfgang Martin Wieland: microscopic amazes copy quantum system like a sea of glass or something that is just rotating and this kind of spin does not this like all with angular momentum this angular momentum is not like a spin that would cover to.
iPhone von Wolfgang Martin Wieland: The other thing degrees of freedom of Lol electron or elementary particle, so this is a subtle.
iPhone von Wolfgang Martin Wieland: distinction between the.
iPhone von Wolfgang Martin Wieland: angular momentum of an.
iPhone von Wolfgang Martin Wieland: spinning top or miss was copied quantum system and the fundamental spin that appears in elementary fields that and only those are sourcing torsion so that.
iPhone von Wolfgang Martin Wieland: So I don't think that.
Christodoulou Marios: which was awesome.
iPhone von Wolfgang Martin Wieland: yeah.
iPhone von Wolfgang Martin Wieland: So I don't think that torsion degrees of freedom will play any role in this kind of experiments as far as I.
Christodoulou Marios: can see this in it's not there's nothing rotating just I don't know.
Christodoulou Marios: How it would come back just to make clear that there's nothing growth, and this is really a.
Christodoulou Marios: Fundamental spin.
Deepak Vaid: These are electrons in degrees, or whatever right, I mean yeah.
Deepak Vaid: I know.
Christodoulou Marios: we're actually discussing this with you will can write about the torsion but I cannot tell you anything wrong, I really have not thought about this.
Christodoulou Marios: sounds interesting but I don't think you might be useful.
Christodoulou Marios: I have no way in my mind to estimate what.
Christodoulou Marios: kind of order of magnitude effect were talking about.
Deepak Vaid: And I mean if I were just just asked us Wolfgang I mean it's not directly related to the.
Deepak Vaid: To the subject here, but we can send it to me any macro distribution with spin would source torsion I thought that is indeed the case.
iPhone von Wolfgang Martin Wieland: Sure, but if, well, it depends on the actual where we are now talking not really about the content of this talk, but.
iPhone von Wolfgang Martin Wieland: You know, it depends up.
iPhone von Wolfgang Martin Wieland: Two points, one is.
iPhone von Wolfgang Martin Wieland: It depends on which coupling you use between the if you're working a first order for relational section, the order of formulation.
iPhone von Wolfgang Martin Wieland: of your your gravitational degrees of freedom and the that the coupling between gravity and spinning degrees of freedom is different, but the coupling of.
iPhone von Wolfgang Martin Wieland: offer of an object it just rotates like they're the moon order moves in the gravitational field, these would never be the source of this would not, this is not this also.
iPhone von Wolfgang Martin Wieland: This is not the kind of angular momentum that sources torsion only.
iPhone von Wolfgang Martin Wieland: Only intrinsic scheme.
iPhone von Wolfgang Martin Wieland: But in any case only intrinsic spin off permissions.
iPhone von Wolfgang Martin Wieland: can be as a source of torsion.
Deepak Vaid: that's that's if you can only coupling why the connection right, but if you if you if you consider the stress energy Center induced by any spinning object right you get a contribution from the.
Deepak Vaid: From that from that from the rotation of that object, whether its intrinsic or extrinsic it doesn't matter.
iPhone von Wolfgang Martin Wieland: What is this is, this is a, this is no.
iPhone von Wolfgang Martin Wieland: I mean the.
iPhone von Wolfgang Martin Wieland: The the the emotional spinning top, for instance in the gravitational field is determined by the by the.
iPhone von Wolfgang Martin Wieland: Top of better equations and they don't are defined for one day I equations for so a connection interstellar that tells you how to spin moves in a gravitational field, but these these these equations for social portion list so that there is.
iPhone von Wolfgang Martin Wieland: These are just we're just getting confused by this discussion on i'm afraid but, and it has nothing to do with the.
iPhone von Wolfgang Martin Wieland: content of my sister you.
iPhone von Wolfgang Martin Wieland: know where to say, I will take.
Christodoulou Marios: Yes, no, thank you for.
Christodoulou Marios: The comments.
iPhone von Wolfgang Martin Wieland: At water I know if I just.
iPhone von Wolfgang Martin Wieland: mentioned something with Yvonne what is kind of missing here is.
iPhone von Wolfgang Martin Wieland: To explain how how it is possible that.
iPhone von Wolfgang Martin Wieland: to neglect back reaction for, for instance at the mathematical every year he knew his satisfies engaged condition, so that they knew that that it's.
iPhone von Wolfgang Martin Wieland: The version less and and also their energy momentum and so then has to satisfy this condition, but this then implies, in turn, that the that your trajectories would move along geodesics, at least in this approximation, so there is a interplay between the.
iPhone von Wolfgang Martin Wieland: covariance divergence of the energy momentum tensor the particles moving.
iPhone von Wolfgang Martin Wieland: Around along geodesics and the gauge conditions to be chosen to be imposed on he knew and all these conditions need to be consistent.
iPhone von Wolfgang Martin Wieland: and
Christodoulou Marios: Here, do you think that first doctor that wouldn't be.
Christodoulou Marios: done, I mean wouldn't be there to this vision, I didn't know I haven't checked and they see what you're saying yes.
Christodoulou Marios: I would be.
iPhone von Wolfgang Martin Wieland: So I will what I think is one only what is missing is to to understand where the external forces are showing up in this in this in this argument and then.
iPhone von Wolfgang Martin Wieland: explain how this is how, by introducing external fields that then lock the particles in certain trajectories, it is possible to make this approximations I think this.
iPhone von Wolfgang Martin Wieland: This would be nice.
Christodoulou Marios: To sync.
Christodoulou Marios: explicitly the magnetic field, be that is somehow.
iPhone von Wolfgang Martin Wieland: coupling your trap or whatever that that moves the particles in some external feel that that makes it.
iPhone von Wolfgang Martin Wieland: yeah this is.
Christodoulou Marios: This, I think that it.
Christodoulou Marios: makes it possible for me to couple this.
Christodoulou Marios: field, the with the.
Christodoulou Marios: know your thing.
iPhone von Wolfgang Martin Wieland: And then you can explain why they are heavy degrees of freedom that you can just.
iPhone von Wolfgang Martin Wieland: That just follow the classic.
iPhone von Wolfgang Martin Wieland: OPS or expect now.
iPhone von Wolfgang Martin Wieland: But in any case, we should continue this.
iPhone von Wolfgang Martin Wieland: Actually.
Ivan Agullo: Is.
Ivan Agullo: And let me take the chance that you are here to ask you.
Ivan Agullo: Your opinion about the question you mentioned at the beginning of your talk this controversy about the fact about the fact that a if our interaction, maybe it's entanglement, it must be a quantum interaction.
Ivan Agullo: What is your opinion about that.
Ivan Agullo: You have an opinion or.
Christodoulou Marios: I do, I think it works, and I think it.
Christodoulou Marios: Does witness not very much, but something about something above nothing.
Christodoulou Marios: It does tell you that it can be a classical field.
Christodoulou Marios: I think, after all this time thinking about they still haven't found exactly the words.
Christodoulou Marios: To say because it does get very confusing.
Christodoulou Marios: I think what is.
Christodoulou Marios: Being overspent was too strong statement is the theory independent so whether they want to say.
Christodoulou Marios: You have two systems and they get entangled.
Christodoulou Marios: By some third system, I assume locality interactions thus whatever theory might be describing this interaction, it must be something based on a non classical field.
Christodoulou Marios: I do not see that you can do that in these experiments, I mean it's it's so just to make sense of what all this means to see what fixed entire theory here and we're still don't understand so.
Christodoulou Marios: You know your belt test, which is a theory it independent.
Christodoulou Marios: test is just under statistics statistics and you say you know, cannot be this type of theories that describe this effect, I think that's too strong.
Christodoulou Marios: speaker again.
Christodoulou Marios: Thank you, thank you very nice discussion.