Tests of general relativity in the nonlinear regime.

by Elisa Maggio (Albert Einstein Institute, Potsdam)

Wednesday Mar 1, 2023, 4:00 PM → 5:00 PM Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

Gravitational waves provide a unique opportunity to test gravity in the dynamical and nonlinear regime. The plunge-merger stage of binary–black-hole coalescences is the region where the bodies’ velocities reach a large fraction of the speed of light and the gravitational-wave luminosity peaks. How much do the predictions of general relativity differ from the ones in other theories of gravity for this stage of the binary evolution? To address this question, we develop a parametrised waveform model that introduces generic deviations to the plunge, merger and ringdown stages of binary-black-hole coalescences. The novel feature of this test is that it can capture signatures of beyond-GR physics in the merger phase of black-hole binaries observed by the LIGO-Virgo-KAGRA Collaboration. We will apply this test to analyse the binary–black-hole events GW150914 and GW200129. The latter event will highlight the importance of waveform systematics and data quality when interpreting tests of general relativity with present gravitational-wave observations.