Measuring the redshift of standard sirens using the neutron star deformability

TL;DR

This paper demonstrates that gravitational wave signals from binary neutron star mergers can be used to directly measure redshift with tens of percent accuracy by analyzing tidal effects, enabling cosmological inference.

Contribution

It advances previous work by using realistic simulations and Bayesian methods to assess redshift measurement accuracy from tidal phasing in gravitational waves.

Findings

Redshift can be measured with tens of percent accuracy.

No significant bias in redshift estimation.

Bayesian inference confirms Fisher Matrix predictions.

Abstract

A recent study has shown that redshift information can be directly extracted from gravitational wave sources. This can be done by exploiting the tidal phasing contributions to the waveform during the inspiral phase of binary neutron stars coalescences. The original study investigated the viability of this idea in the context of the Einstein Telescope using a Fisher Matrix approach and in this paper, we further explore this idea using realistic simulations and Bayesian inference techniques. We find that the fractional accuracy with which the redshift can be measured is in the order of tens of percent, in agreement with Fisher Matrix predictions. Moreover, no significant bias is found. We conclude that, when tidal phasing contributions are included in the analysis, inference of the cosmological parameters from gravitational waves is possible