Relativistic stars in mass-varying massive gravity

TL;DR

This paper explores how mass-varying massive gravity affects neutron stars and white dwarfs, revealing that the graviton mass varies significantly near these stars and influences their structural properties, with implications for constraining the theory.

Contribution

It demonstrates the existence of multiple compact star solutions with radially varying graviton mass and analyzes their impact on mass-radius relations in mass-varying massive gravity.

Findings

Graviton mass becomes large near compact stars and diminishes away from them.

Existence of a tower of solutions with radially decreasing graviton mass.

Mass-radius relations are significantly affected by the graviton mass variations.

Abstract

Mass-varying massive gravity allows the graviton mass to vary according to different environments. We investigate neutron star and white dwarf solutions in this theory and find that the graviton mass can become very large near the compact stars and settle down quickly to small cosmological values away the stars, similar to that of black holes in the theory. It is found that there exists a tower of compact star solutions where the graviton mass decreases radially to zero non-trivially. We compute the massive graviton effects on the mass-radius relations of the compact stars, and also compare the relative strengths between neutron stars and white dwarfs in constraining the parameter space of mass-varying massive gravity.