Dark Sirens to Resolve the Hubble-Lema\^itre Tension

TL;DR

This paper discusses how future gravitational-wave detector upgrades and higher order modes can accurately identify host galaxies of dark sirens, enabling precise independent measurements of the Hubble constant to resolve the current tension.

Contribution

It introduces the potential of upgraded detectors and higher modes to improve dark siren localization and redshift measurement for cosmology.

Findings

Dark sirens can be localized within their host galaxies with future upgrades.

Higher order modes improve distance and localization accuracy.

H0 can be measured to better than a few percent within five years.

Abstract

The planned sensitivity upgrades to the LIGO and Virgo facilities could uniquely identify host galaxies of dark sirens-compact binary coalescences without any electromagnetic counterparts-within a redshift of z = 0.1. This is aided by the higher order spherical harmonic modes present in the gravitational-wave signal, which also improve distance estimation. In conjunction, sensitivity upgrades and higher modes will facilitate an accurate, independent measurement of the host galaxy's redshift in addition to the luminosity distance from the gravitational wave observation to infer the Hubble-Lema\^itre constant H0 to better than a few percent in five years. A possible Voyager upgrade or third generation facilities would further solidify the role of dark sirens for precision cosmology in the future.