Modified gravitational wave propagation and the binary neutron star mass function

TL;DR

This paper explores how modified gravity affects gravitational wave signals from binary neutron stars, proposing that the narrow mass distribution of these stars can reveal signatures of such modifications at high redshifts.

Contribution

It demonstrates that the effect of modified GW propagation on mass reconstruction can serve as a clear signature of modified gravity, especially with future third-generation detectors.

Findings

Modified gravity alters the inferred masses of neutron star binaries.

The narrow mass distribution of neutron stars enhances detection of modified gravity effects.

Third-generation GW detectors can identify these signatures at high redshifts.

Abstract

Modified gravitational wave (GW) propagation is a generic phenomenon in modified gravity. It affects the reconstruction of the redshift of coalescing binaries from the luminosity distance measured by GW detectors, and therefore the reconstruction of the actual masses of the component compact stars from the observed (`detector-frame') masses. We show that, thanks to the narrowness of the mass distribution of binary neutron stars, this effect can provide a clear signature of modified gravity, particularly for the redshifts explored by third generation GW detectors such as Einstein Telescope and Cosmic Explorer.