http://arxiv.org/abs/1904.08011
We propose a hierarchical approach to testing general relativity with multiple gravitational wave detections. Unlike existing strategies, our method does not assume that parameters quantifying deviations from general relativity are either common or completely unrelated accross all sources. We instead assume that these parameters follow some underlying distribution, which we parametrize and constrain. This can be then compared to the distribution expected from general relativity, i.e. no deviation in any of the events. We demonstrate that our method is robust to measurement uncertainties and can be applied to theories of gravity where the parameters beyond general relativity are related to each other, as generally expected. Our method contains the two extremes of common and unrelated parameters as limiting cases. We apply the hierarchical model to the population of 10 binary black hole systems so far detected by LIGO and Virgo. We do this for a parametrized test of gravitational wave generation, by assuming that the beyond-general-relativity parameters follow a Gaussian distribution. We compute the posterior distribution for the mean and the variance of the population and show that both are consistent with general relativity.
M. Isi, K. Chatziioannou and W. Farr
Thu, 18 Apr 19
72/75
Comments: 5 pages, 3 figures