Probing Cosmology with Baryon Acoustic Oscillations using Gravitational Waves

The third-generation (3G) GW detectors such as the Einstein telescope (ET) or Cosmic Explorer (CE) are expected to play an important role in cosmology. With the help of 3G detectors, we will be able to probe the large-scale structure (LSS) features such as baryon acoustic oscillations (BAO), galaxy bias, etc. We explore the possibility to do precision cosmology, with the 3G GW detectors by measuring the angular BAO scale using localization volumes of compact binary merger events. The BAO are the imprints of the early Universe on the distribution of matter and it provides a standard scale which can be treated as a cosmic ruler. Through simulations, we show that with a 3G detector network, by probing the angular BAO scale using purely GW observations, we can constrain the Hubble constant for the standard model of cosmology ($\Lambda$CDM) with $90\%$ credible regions as $H_0 = 64.01^{+ 15.25}_{-14.47}$. When combined with BAO measurements from galaxy surveys, we show that it can be used to constrain various models of cosmology such as parametrized models for dark energy equations of state