Nicola Borghi
|
A cosmological-model-independent reconstruction of the expansion history of the Universe can shed light on the dark sector and current cosmological tensions. I will discuss past, present, and future efforts to constrain the Hubble parameter using two novel and complementary probes: cosmic chronometers (CCs) and gravitational waves (GWs). In the first part, I will present the CC method and recent CC results based on the study of the stellar population of intermediate-redshift passive galaxies. In the second part, I will discuss the GW standard sirens method and present predictions for joint cosmological and astrophysical constraints from black hole binary mergers for the upcoming LIGO-Virgo-KAGRA detectors and galaxy surveys. These two probes already provide an independent reconstruction of H(z) with direct measurements of H0 from GWs and H(z) up to z ∼ 2 from CCs and represent promising avenues to unveil the expansion history of the Universe.
|