Orateur
Description
The expansion of the Universe is well established, yet the current value of the Hubble constant, H0,
remains a subject of ongoing debate. Direct measurements based on Type Ia supernovae and Cepheid variables yield values significantly higher than those inferred from early-Universe observations of the cosmic microwave background, dating back approximately 13 billion years.
An independent approach to measuring H0 relies on gravitational-wave (GW) signals from kilonova events, which can simultaneously provide both distance and redshift—two key observables for determining the Hubble constant. However, only a single such event has been detected so far, resulting in a measurement with large uncertainties.
In this thesis, we propose a novel method that can be applied to any gravitational-wave event. It is based on a statistical matching between the matter density distribution inferred from gravitational-wave observations and that obtained from supernovae and galaxy surveys.
In this presentation, I will outline the conceptual framework of this method and present the preliminary work required for its implementation on both the gravitational-wave and Type Ia supernova data.