Speaker
Description
The LIGO-Virgo-Kagra (LVK) collaboration uses a subset of 47 gravitational-wave (GW) events from the third observing run to constrain the cosmology and in particular the Hubble constant $H_0$. The Hubble constant can be constrained using the luminosity distance inferred from each GW signals of compact binary coalescence, combined with an estimation of their corresponding redshift. Two approaches are employed: the first one investigates the mass-redshift degeneracy and the second one makes use of an external galaxy catalog. The first method uses the mass-redshift degeneracy of the binary black-hole (BBH). By breaking this degeneracy, the cosmological parameters are inferred jointly along with the population of BBH systems. When combined with the binary neutron star event GW170817, the Hubble constant is estimated at $H_0 = 68^{+12}_{-8}km.s^{-1}.Mpc^{-1}$ ($68\% CI$). On the other hand, the galaxy catalog method statistically associates each BBHs source to its potential host galaxy, then infers the redshift from these galaxies’ information. Under the assumption of a fixed population model of BBHs, the Hubble parameter is estimated at $H_0 = 68^{+8}_{-6}km.s^{-1}.Mpc^{-1}$, which represents a 42% improvement in uncertainty compared to the value inferred from the first observing run of LVK. In the future, GW detections may play a significant role for cosmology, bringing a discriminating measurement of $H_0$ in the context of the Hubble tension.
Details
Grégoire PIERRA
PhD student (1st year)
Institut de physique des 2 infinis
FRANCE, Lyon 69000
https://annuaire.in2p3.fr/6847-9632/gregoire-pierra
https://www.ip2i.in2p3.fr/equipes/ondes-gravitationnelles/
| Is this abstract from experiment? | Yes |
|---|---|
| Name of experiment and experimental site | LIGO-Virgo Interferometers (Hanford, Livingston and Cascina) |
| Is the speaker for that presentation defined? | Yes |
| Internet talk | No |
