Parameterized tests of the strong-field dynamics of general relativity using gravitational wave signals from coalescing binary black holes: Fast likelihood calculations and sensitivity of the method

TL;DR

This paper enhances tests of general relativity using gravitational wave data by developing fast likelihood methods, demonstrating robustness, and assessing the sensitivity of the approach to potential deviations from GR.

Contribution

It introduces reduced-order quadratures for rapid likelihood calculations and evaluates the robustness and sensitivity of parametrized tests of GR with gravitational wave signals.

Findings

Likelihood calculations are significantly sped up.

Tests correctly identify consistency with GR when valid.

Method's sensitivity to GR violations is quantitatively assessed.

Abstract

Thanks to the recent discoveries of gravitational wave signals from binary black hole mergers by Advanced Laser Interferometer Gravitational Wave Observatory and Advanced Virgo, the genuinely strong-field dynamics of spacetime can now be probed, allowing for stringent tests of general relativity (GR). One set of tests consists of allowing for parametrized deformations away from GR in the template waveform models and then constraining the size of the deviations, as was done for the detected signals in previous work. In this paper, we construct reduced-order quadratures so as to speed up likelihood calculations for parameter estimation on future events. Next, we explicitly demonstrate the robustness of the parametrized tests by showing that they will correctly indicate consistency with GR if the theory is valid. We also check to what extent deviations from GR can be constrained as information from an increasing number of detections is combined. Finally, we evaluate the sensitivity of the method to possible violations of GR.