SU(2) cosmological solitons

C. Lechner, S. Husa, P. C. Aichelburg
2000 Physical Review D, Particles and fields  
We present a class of numerical solutions to the SU(2) nonlinear σ-model coupled to the Einstein equations with cosmological constant Λ≥ 0 in spherical symmetry. These solutions are characterized by the presence of a regular static region which includes a center of symmetry. They are parameterized by a dimensionless "coupling constant" β, the sign of the cosmological constant, and an integer "excitation number" n. The phenomenology we find is compared to the corresponding solutions found for
more » ... Einstein-Yang-Mills (EYM) equations with positive Λ (EYMΛ). If we choose Λ positive and fix n, we find a family of static spacetimes with a Killing horizon for 0 ≤β < β_max. As a limiting solution for β = β_max we find a globally static spacetime with Λ=0, the lowest excitation being the Einstein static universe. To interpret the physical significance of the Killing horizon in the cosmological context, we apply the concept of a trapping horizon as formulated by Hayward. For small values of β an asymptotically de Sitter dynamic region contains the static region within a Killing horizon of cosmological type. For strong coupling the static region contains an "eternal cosmological black hole".
doi:10.1103/physrevd.62.044047 fatcat:2j5xxzd33ne2lnog2w2ji6hp24