Current and future constraints on cosmology and modified gravitational wave friction from binary black holes

Understand

In this proceedings, we are interested in dark gravitational wave standard sirens and their use for cosmology and for constraining modified gravity theories.

• Due to the extra friction term introduced in their propagation equation those theories predict different luminosity distances for electromagnetic and gravitational waves (GWs).
• This effect can be parametrized by the two variables $\Xi_0$ and $n$, that can be measured from gravitational wave observations, and specifically from the binary black hole (BBH) mergers detected by LIGO and Virgo.
• By fitting jointly BBH population models in mass and redshift, the cosmological parameters, and the modified GW luminosity distance to $\sim$ 60 signals observed during the first three LIGO/Virgo observation runs, we conclude that general relativity is consistently the preferred model.