http://arxiv.org/abs/2004.05974
We show how by careful monitoring of the inspiral signal from a compact object binary in ground-based gravitational wave (GW) detectors one can test if its components are black holes or not. Here we limit ourselves to black holes (with and without spin) in General Relativity. Such objects are characterized by horizons, which absorb gravitational radiation from the orbit during their inspiral in a binary, via a phenomenon known as tidal heating. By contrast, a compact object such as a neutron star has minimal tidal heating — but has tidal deformation — and affects the phase evolution of binaries containing it in a distinctly different way. Here we identify waveform parameters that characterize the strength of tidal heating, and are zero when there is no horizon absorption. We demonstrate how by using those parameters Bayesian methods can distinguish the presence or absence of horizons in a binary. This is a particularly exciting prospect owing to several claims that these stellar-mass objects, with masses heavier than those of neutron stars, may not have a horizon but may be black hole mimickers or exotic compact objects. Perhaps more significant is the possibility that our method can be used to test the presence or absence of horizons in mass-gap binaries and, thereby, help detect the heaviest neutron star or the lightest black hole. A proper accounting of tidal heating in binary waveform models will also be critical for an unbiased measurement of characteristics of the equation of state of neutron stars in GW observations of binaries containing them — or even to probe the existence of exotic compact objects.
S. Datta, K. Phukon and S. Bose
Tue, 21 Apr 20
34/90
Comments: N/A