Gravitational collapse of anisotropic stars

Abstract

We study the gravitational collapse of a spherically symmetric anisotropic relativistic star within Einstein theory of gravity making use of one of our recently developed collapsing stellar models [{\it Astrophys. Space Sci.} {\bf361} 99 (2016)]. The final state of continual gravitational collapse of a massive star under regular initial conditions is analyzed in terms of the formation of black holes. To study the evolution of an anisotropic star undergoing gravitational collapse, it is assumed that the dissipation process happens in the form of radial heat-flux. The interior space-time is described by static metric matched at the boundary with Vaidya metric that describes the exterior to the radiating star. The initial static configuration is described by the relativistic solution obtained by Paul and Deb [{\it Astrophys. Space Sci.} {\bf354} 421 (2014)]. The impact of anisotropy on the dynamical gravitational collapse of a massive star is studied. The relativistic causal heat transport equation of the Maxwell-Cattaneo equation is utilized to show the dependence of anisotropy on the temperature profile of the collapsing system.