Boson Stars Collisions
Let us consider binary bosons stars which are described with the same global
scalar field φ.
The initial data is constructed by simple superposition
φ = φ1(r-r1,v1)
+ φ2(r-r2,v2)
being φi the initial data for the single boson star i centered
at ri and boosted with a speed vi.
The U(1) symmetry allows to introduce modifications on the imaginary part of the
scalar field solution, so we will consider
φ1 = φ0(r)
e i ϖ t
φ2 = φ0(r)
e i ε ϖ t + θ
where ε = +1 corresponds to a boson star and ε = -1 to an antiboson one.
Notice that there can be also a phase difference θ between the stars.
Head-on collisions
- Boson/boson pair (ε = +1, θ = 0)
- Metric component g11
- Scalar field φ
- Boson/boson in opposition of phase pair (ε = +1, θ = π)
- Metric component g11
- Scalar field φ
Orbiting systems
- Boson/boson pair (ε = +1, θ = 0, Jz = 0.8)
- energy density ρ
- Boson/boson pair (ε = +1, θ = 0, Jz = 1.0)
- energy density ρ
- Boson/antiboson pair (ε = -1, θ = 0, Jz = 0.8)
- energy density ρ
- Boson/antiboson pair (ε = -1, θ = 0, Jz = 1.0)
- energy density ρ
- Boson/boson in opposition of phase pair (ε = +1, θ = π , Jz = 1.0)
- energy density ρ
Parameter survey for the orbiting boson/boson pair
- v= 0.0 : head on collision forming a black hole
- energy density ρ
- v= 0.052 : merge into a rotating bar which splits in two pieces
- energy density ρ
- Scalar field φ (log scale)
- v= 0.064 : merge into a rotating bar which disperses scalar field
- energy density ρ
- Scalar field φ (log scale)
- v= 0.072 : merge into a rotating bar which bounds until form a black hole
- energy density ρ
- Scalar field φ (log scale)
- v= 0.082 : merge into a kerr black hole
- energy density ρ
- Scalar field φ (log scale)