Extreme gravity tests with gravitational waves from compact binary coalescences: (I) inspiral–merger

Abstract

The observation of the inspiral and merger of compact binaries by the LIGO/Virgo collaboration ushered in a new era in the study of strongfield gravity. We review current and future tests of strong gravity and of the Kerr paradigm with gravitational-wave interferometers, both within a theoryagnostic framework (the parametrized post-Einsteinian formalism) and in the context of specific modified theories of gravity (scalar-tensor, Einstein-dilaton-Gauss-Bonnet, dynamical Chern-Simons, Lorentz-violating, and extra dimensional theories). In this contribution we focus on (i) the information carried by the inspiral radiation, and (ii) recent progress in numerical simulations of compact binary mergers in modified gravity.

Parametrized and inspiral-merger-ringdown consistency tests of gravity with multiband gravitational wave observations

“…are the dimensionless EdGB BH scalar charges normalized by the masses [73,110], where χ i ≡ | S i |/m 2 i are the dimensionless spins of BHs with spin angular momentum S i . The ppE exponent is b = −7 in this theory, which means that the leading correction enters at −1PN order.…”

Probing beyond-Kerr spacetimes with inspiral-ringdown corrections to gravitational waves

“…We find each method to agree very well with each other, and see that future detectors have the ability to constrain both 3 and β very stringently. With currentgeneration GW detectors, we find comparable constraints on the JP deviation parameter 3 to those from x-ray ob-servations of BH accretion disks [79,80], found to be loosely 3 5. With future space-based and groundbased GW observatories, we find constraints a few orders of magnitude stronger.…”

“…The famous observation of gravitational waves (GWs) from the distant coalescence of two black holes (BHs) has opened the window for a new probe of the extreme gravity spacetimes [1][2][3] present around such objects. Observed by the Laser Interferometer Gravitational-wave Observatory [4] (LIGO) on September 14, 2015, the impressive observation of GW150914 [5] was only the first of eleven GW events detected [6].…”

“…Just as previously, Newtonian's prescription of gravity was relentlessly tested, we now must put GR to the test. Since then, GR has been subject to observations in a variety of different spacetime environments, including within the solar system where gravity is weak and static [7], in strong and static-field binary pulsar systems [8,9], in large-scale cosmological observations [10][11][12][13][14], and finally in the extreme-gravity observations of GWs [1][2][3][15][16][17][18]. In every scenario, all such tests of GR have been found to agree remarkably with Einstein's theory.…”

“…In this paper, we focus our attentions on two parameterized metrics and see how well one can probe such spacetimes with current and future GW observations. The first one was derived by Johannsen and Psaltis (JP) [37], which has a single deviation parameter 3 . This spacetime is an example of the more general metric found in [40].…”