Publication date: Jun 2012
Abstract:
Extremely compact stars (ECS) (having radius R < 3 GM/ c
2) contain captured null geodesics. Certain part of neutrinos
produced in their interior will be trapped, influencing thus their
neutrino luminosity and thermal evolution. The trapping effect has been
previously investigated for the internal Schwarzschild spacetimes with
the uniform distribution of energy density. Here, we extend our earlier
study considering the influence of the cosmological constant Λ on
the trapping phenomena. Our model for the interior of ECS is based on
the internal Schwarzschild-(anti-)de Sitter (S(a)dS) spacetimes with
uniform distribution of energy density matched to the external vacuum
S(a)dS spacetime with the same cosmological constant. Assuming uniform
and isotropic distribution of local neutrino emissivity we determine
behavior of the trapping coefficients, i.e., "global" one representing
influence on the neutrino luminosity and "local" one representing
influence on the cooling process. We demonstrate that the repulsive
(attractive) cosmological constant has tendency to enhance (damp) the
trapping phenomena.
Authors:
Stuchlík, Zdeněk; Hladík, Jan; Urbanec, Martin; Török, Gabriel;