Blackhole ringdown as a probe of highercurvature gravity theories
Abstract
Detecting gravitational waves from coalescing compact binaries allows us to explore the dynamical, nonlinear regime of general relativity and constrain modifications to it. Some of the gravitationalwave events observed by the LIGOVirgo Collaboration have sufficiently high signaltonoise ratio in the merger, allowing us to probe the relaxation of the remnant black hole to its final, stationary state—the socalled blackhole ringdown, which is characterized by a set of quasinormal modes. Can we use the ringdown to constrain deviations from general relativity, as predicted by several of its contenders? Here, we address this question by using an inspiralmergerringdown waveform model in the effectiveonebody formalism, augmented with a parametrization of the ringdown based on an expansion in the final black hole's spin. We give a prescription on how to include in this waveform model, the quasinormal mode frequencies calculated on a theorybytheory basis. In particular, we focus on theories that modify general relativity by higherorder curvature corrections, namely, EinsteindilatonGaussBonnet, dynamical ChernSimons theories, and cubic and quarticorder effectivefieldtheories of general relativity. We use this parametrized waveform model to measure the ringdown properties of the two loudest ringdown signals observed so far, GW150914 and GW200129. We find that while the EinsteindilatonGaussBonnet theory cannot be constrained with these events, we can place upper bounds on the fundamental lengthscale of cubic (ℓcEFT≤38.2_{km ) and quarticorder (ℓqEFT}≤51.3_{km)effectivefieldtheories of general relativity, and of dynamical ChernSimons gravity (ℓdCS≤38.7 km ). The latter result is a concrete example of a theory presently unconstrained by inspiralonly analyses which, however, can be constrained by mergerringdown studies with current gravitationalwave data. }
 Publication:

Physical Review D
 Pub Date:
 February 2023
 DOI:
 10.1103/PhysRevD.107.044030
 arXiv:
 arXiv:2205.05132
 Bibcode:
 2023PhRvD.107d4030S
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  High Energy Astrophysical Phenomena;
 High Energy Physics  Theory
 EPrint:
 21 pages, 12 figures. v2. Matches published version