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Nonsingular Spherical Models with a Variable Cosmological term

Anirudh Pradhan·Kashika Srivastava·Amrit Lal Ahuja
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Abstract

Exact solutions of the Einstein's field equations describing a spherically symmetric cosmological model without a big bang or any other kind of singularity recently obtained by Dadhich and Patel (2000) are revisited. The matter content of the model is a shear-free perfect fluid with isotropic pressure and a radial heat flux. Three different exact solutions are obtained for both perfect fluid and fluid with bulk viscosity. It turns out that the cosmological rerm $Λ(t)$ is a decreasing function of time, which is consistent with recent observations of type Ia supernovae.

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Anirudh Pradhan, Kashika Srivastava, Amrit Lal Ahuja. 2007-03-09. Nonsingular Spherical Models with a Variable Cosmological term. https://arxiv.org/abs/gr-qc/0408057

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