We investigate the role played by density inhomogeneities and dissipation on the final outcome of collapse of a self-gravitating sphere. By imposing a perturbative scheme on the thermodynamical variables and gravitational potentials we track the evolution of the collapse process starting off with an initially static perfect fluid sphere which is shear-free. The collapsing core dissipates energy in the form of a radial heat flux with the exterior spacetime being filled with a superposition of null energy and an anisotropic string distribution. The ensuing dynamical process slowly evolves into a shear-like regime with contributions from the heat flux and density fluctuations. We show that the anisotropy due to the presence of the strings drives the stellar fluid towards instability with this effect being enhanced by the density inhomogeneity. An interesting and novel consequence of this collapse scenario is the delay in the formation of the horizon. Keywords radiative collapse • anisotropic stresses • density inhomogeneities 1 Introduction Gravitational collapse is fundamental to the formation of the majority of stellar objects in the universe and thus one would expect that the study of this

In this work we present a general framework for obtaining exact solutions to the Einstein field equations describing strange stars obeying a colour-flavour-locked (CFL) equation of state. Starting off with a spherically symmetric metric in isotropic coordinates describing the interior of the star, we impose a CFL equation of state to reduce the problem to a single-generating function of the gravitational potentials. Our approach leads to an infinite class of solutions of the field equations. In order to test the physical viability of our solutions, we subscribe a particular model to stringent stability tests. In particular, we show that a linear equation of state described by the MIT Bag model mimics the CFL equation of state describing strange stars with interacting quark matter. This is an interesting result which connects the more robust and mathematically tractable linear equation of state to the fundamental physics describing nuclear matter in the quark regime.

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