Stephani Cosmology: Entropically Viable But Observationally Challenged

TL;DR

This paper evaluates the Stephani-Dabrowski cosmological model, finding it entropically viable but facing observational challenges, similar to other inhomogeneous models like LTB, despite satisfying some theoretical principles.

Contribution

It provides a detailed analysis of the Stephani-Dabrowski model's entropic viability and observational constraints, highlighting its theoretical strengths and practical limitations.

Findings

Model is entropically viable

Struggles to meet all observational constraints

Satisfies the holographic principle

Abstract

Inhomogeneous cosmological models such as the Stephani universes could, in principle, provide an explanation for the observed accelerated expansion of the Universe. Working with a concrete, popular model of the Stephani cosmology -- the Stephani-Dabrowski model, we found that it is entropically viable. We also comment on the energy conditions and the two-sheeted geometry of the spacetime. However, similar to the LTB models, despite satisfying the holographic principle, Stephani cosmology has difficulty satisfying all the constraints from observations.