Einstein's Theory of Gravity in the Presence of Pressure: A Review

TL;DR

This review discusses how Einstein's theory of gravity predicts that pressure contributes to gravitational effects, highlighting inconsistencies in current models of dark energy and the universe's matter content.

Contribution

It critically examines the implications of pressure in Einstein's gravity theory and identifies unresolved issues in modeling dark energy with the energy-stress tensor.

Findings

Pressure gravitates according to Einstein's theory

Inconsistencies in the energy-stress tensor with pressure

Potential need for revised gravitational models

Abstract

The mysterious `dark energy' needed to explain the current observations, poses a serious confrontation between fundamental physics and cosmology. The present crisis may be an outcome of the (so far untested) prediction of the general theory of relativity that the pressure of the matter source also gravitates. In this view, a theoretical analysis reveals some surprising inconsistencies and paradoxes faced by the energy-stress tensor (in the presence of pressure) which is used to model the matter content of the universe, including dark energy.