Tidal Love numbers of neutron stars in Rastall gravity

TL;DR

This paper extends the theory of neutron star tidal deformability to Rastall gravity, showing that Love numbers are significantly smaller than in general relativity, highlighting degeneracy between gravity modifications and nuclear matter equations.

Contribution

It introduces a novel extension of tidal deformability calculations to Rastall gravity and compares results with general relativity, revealing key differences.

Findings

Neutron star tidal Love numbers are smaller in Rastall gravity.

Results suggest degeneracy between gravity modifications and nuclear matter equations.

Provides new insights into gravitational effects on neutron star structure.

Abstract

Gravitational-wave measurements of the tidal deformability of neutron stars could reveal important information regarding their internal structure, the equation of state of high-dense nuclear matter and gravity in strong field regime. In this work, we extend the relativistic theory of the tidal deformability of neutron stars to Rastall gravity. Both the electric-type and magnetic-type quadrupole tidal Love numbers are calculated for neutron stars in the polytrope model. It is found that neutron star's tidal Love numbers in Rastall gravity is significantly smaller than those in general relativity. Our results provide new evidence of the degeneracy between the modification of gravity and the equation of state of nuclear matter in neutron stars.