Dynamics of uniformally collapsing system and the horizon formation

Abstract

In astrophysics studies, the stellar system (e.g. stars, etc.) is generally considered a spherically symmetric object, and its evolutions (e.g. collapse) depends on the nature of fluid distribution and kinematical properties that are not precisely known. One generally makes additional restrictions allowing the integration of the field equations for the studies of dynamical models. This work deals with the spherically symmetric stellar system with uniform expansion scalar ([Formula: see text]) describing the uniform collapse of stars. The uniform expansion scalar describes an important physical scenario (a generalization of the OSD model) that will exhibit a new class of collapsing stars. Here, we have parameterized the expansion scalar as exponential, power law and their combination form as a function of time [Formula: see text] so that it describes the collapsing configuration [Formula: see text]. The formation of black-hole, the horizon surface, and the thermal behavior of black-hole has also been discussed. Further, we have discussed the dynamics of uniformly collapsing system for conformally flatness. The uniform motion (collapse) of any stellar system is a fascinating phenomenon therefore the present works will produce new aspects for the studies of collapsing stellar systems and may generate broad interest among astrophysicists.