Speaker
Description
Asymmetric binaries, such as extreme- and intermediate-mass-ratio inspirals, are prime targets of future gravitational-wave detectors and offer a unique opportunity to probe the astrophysical environments in which such binaries evolve, as well as to test possible deviations from general relativity. To date, these two classes of effects — beyond-vacuum environmental physics and beyond-GR modifications — have largely been modelled independently, as small perturbations to the baseline vacuum-GR dynamics. In realistic astrophysical scenarios, however, both effects can act simultaneously, jointly shaping the binary's evolution and the resulting parameter estimation. In this talk, I will present a rigorous framework for describing the interplay between (scalar) fields associated with beyond-vacuum environments and with modifications to gravity, built on a perturbative approach inspired by self-force calculations in vacuum GR. Focusing on specific examples, I will then show how these two effects become correlated, and how this correlation impacts the detectability of both environmental and gravitational-modification signatures.