Dilation Dark Matter in Vaidya-De-Sitter Spacetime

TL;DR

This paper explores solutions to Einstein's field equations in Vaidya-De Sitter spacetime, revealing how dark matter and scalar fields influence the structure of a relativistic star's atmosphere.

Contribution

It introduces new analytical solutions involving dilaton scalar fields coupled with dark matter in Vaidya-De Sitter spacetime, extending classical models.

Findings

Classical de Sitter universe recovered in static case

Extended de Sitter metric coupled with scalar field in time-dependent case

Atmosphere consists of anisotropic string fluid with dark matter null fluid

Abstract

The exterior of a relativistic star can be modelated with the Vaidya radiating metric. It is started from the generalized Vaidya metric that allows a type II fluid and studied the conditions of generating new analytical solutions of the Einstein's field equations. It is shown that the mass parameter solution gives the classical de Sitter universe in the static case and the extended de Sitter metric coupled with a dilation scalar field in the time-dependent case. It is concluded that in the time-dependent case the atmosphere of a relativistic star consists on an anisotropic string fluid coupled with a dark matter null fluid and interpreted the scalar field as the particle that produces the dark matter.