Temporal evolution of a radiating star via Lie symmetries

In this work we present for the first time the general solution of the temporal evolution equation arising from the matching of a conformally flat interior to the Vaidya solution. This problem was first articulated by Banerjee et al. (Phys Rev D 40:670, 1989) in which they provided a particular solution of the temporal equation. This simple exact solution has been widely utilised in modeling dissipative collapse with the most notable result being prediction of the avoidance of the horizon as the collapse proceeds. We study the dynamics of dissipative collapse arising from the general solution obtained via the method of symmetries and of the singularity analysis. We show that the end-state of collapse for our model is significantly different from the widely used linear solution.

Stellar shear-free gravitational collapse with Karmarkar condition in f(R) gravity

This work has investigated the outcomes of spherically symmetric radiating dissipative gravitational collapse model with anisotropic heat conducting matter distribution by imposing time-dependent Karmarkar condition in the alternative [Formula: see text] theory of gravity. For this evaluation, we defined the smooth matching conditions between the interior space–time and exterior Vaidya solution at the junction interface. Afterwards, we have found an exact particular solution of our radiative star model by using the Karmarkar condition. Moreover, the physical components of the matter distribution, energy conditions and time relaxational effects on the temporal profile are thoroughly discussed with graphical analysis which indicates the system is well behaved.

Vaidya solution in general covariant Hořava–Lifshitz gravity with the minimum coupling and without projectability: Infrared limit

In this paper, we have studied nonstationary radiative spherically symmetric spacetime, in general covariant theory (U(1) extension) of the Hořava–Lifshitz gravity with the minimum coupling, in the parameterized post-Newtonian (PPN) approximation, without the projectability condition and in the infrared limit. The Newtonian prepotential φ was assumed null. We have shown that there is not the analog of the Vaidya's solution in the Hořava–Lifshitz Theory with the minimum coupling, as we know in the General Relativity Theory (GRT).