Shear-dependent Pressure in a Lema\^itre-Tolman-Bondi Metric

TL;DR

This paper investigates how shear-dependent pressure in a Lemaître-Tolman-Bondi metric, combined with dark energy, can explain the observed dimming of distant supernovae, offering an alternative to dark energy alone.

Contribution

It introduces a model where dark energy pressure depends on shear in an LTB metric, providing a novel approach to cosmic acceleration explanations.

Findings

Shear-dependent dark energy pressure affects supernova dimming.

The model links shear ratio to dark energy behavior.

Potential to explain observations without standard dark energy assumptions.

Abstract

We propose to explain the dimming of distant supernovae as the combined effect of dark energy and a Lema\^itre-Tolman-Bondi (LTB) metric. We take dark energy to have a shear-dependent pressure $p_{DE}=(w_0+\epsilon w_1)\rho_{DE}$ where $\epsilon$ is the ratio of LTB shear to LTB expansion.