The impact of AGN environmental effects on testing general relativity with space-borne gravitational wave detector

TL;DR

This paper demonstrates that space-borne gravitational wave detectors can effectively distinguish dipole radiation signals from environmental effects in binary black hole systems, ensuring robust tests of general relativity in realistic astrophysical settings.

Contribution

The study shows that environmental effects do not hinder the detection of dipole radiation when both are modeled simultaneously in Bayesian inference, supporting future gravity tests.

Findings

Environmental effects can be modeled without losing dipole radiation detectability.

Dipole parameters can be recovered with high precision despite environmental influences.

Environmental effects do not prevent identifying deviations from general relativity.

Abstract

The space-borne gravitational wave detectors such as TianQin offers a new window to test General Relativity by observing the early inspiral phase of stellar-mass binary black holes. A key concern arises if these stellar-mass binary black holes reside in gaseous environments such as active galactic nucleus accretion disks, where environmental effects imprint detectable modulations on the gravitational waveform. Using Bayesian inference on simulated signals containing both environmental and dipole deviation, we have assessed the extent to which the presence of environmental effects affects the detectability of dipole radiation. Our results demonstrate that even in the presence of strong environmental coupling, the dipole parameter can be recovered with high precision, and the evidence for dipole radiation remains distinguishable. Crucially, we find that the existence of environmental effects does not fundamentally impede the identification of dipole radiation, provided both effects are simultaneously modelled in the inference process. This study establishes that future tests of modified gravity with space-borne observatories can remain robust even for sources in astrophysical environments.