TITLE:
Vaidya Solution in Non-Stationary de Sitter Background: Hawking’s Temperature
AUTHORS:
Ngangbam Ishwarchandra, Kangujam Yugindro Singh
KEYWORDS:
Vaidya Solution; Non-Stationary de Sitter; Einstein’s Equations; Energy-Momentum Tensor
JOURNAL NAME:
International Journal of Astronomy and Astrophysics,
Vol.3 No.4,
December
16,
2013
ABSTRACT: In this paper we propose a class of non-stationary
solutions of Einstein’s field equations describing an embedded Vaidya-de Sitter
solution with a cosmological variable function Λ(u). Vaidya-de Sitter
solution is interpreted as the radiating Vaidya black hole which is embedded
into the non-stationary de Sitter space with variable Λ(u). The energymomentum
tensor of the Vaidya-de Sitter black hole may be expressed as the sum of the
energy-momentum tensor of the Vaidya null fluid and that of the non-stationary
de Sitter field, and satisfies the energy conservation law. We also find that
the equation of state parameter w= p/ρ = -1 of the
non-stationary de Sitter solution holds true in the embedded Vaidya-de Sitter
solution. It is also found that the space-time geometry of non-stationary
Vaidya-de Sitter solution with variable Λ(u) is type D in the Petrov
classification of space-times. The surface gravity, temperature and entropy
of the space-time on the cosmological black hole horizon are discussed.