Neutron Stars in Rastall Gravity

TL;DR

This paper investigates neutron star solutions within Rastall gravity, a modified theory where energy-momentum conservation is relaxed, and constrains its deviations from general relativity using realistic equations of state.

Contribution

It provides the first detailed neutron star solutions in Rastall gravity and establishes stringent bounds on its deviation from general relativity.

Findings

Rastall gravity can describe neutron stars with realistic equations of state.

Deviations from GR in Rastall gravity are constrained to be less than 1%.

The work sets new limits on non-GR effects in neutron star physics.

Abstract

We calculate static and spherically symmetric solutions for the Rastall modification of gravity to describe Neutron Stars (NS). The key feature of the Rastall gravity is the non-conservation of the energy-momentum tensor proportionally to the space-time curvature. Using realistic equations of state for the NS interior we place a conservative bound on the non-GR behaviour of the Rastall theory which should be $\lesssim 1\%$ level. This work presents the more stringent constraints on the deviations of GR caused by the Rastall proposal.