Speaker
Description
Gravitational-wave observations have opened a new window on the strong-gravity regime of General Relativity. While most detected signals are interpreted assuming isolated compact binaries, many astrophysical systems are expected to evolve in complex environments, such as the dense regions surrounding supermassive black holes in galactic nuclei. In these scenarios, external gravitational fields can significantly influence the dynamics of compact binaries and leave measurable imprints on their gravitational-wave emission.
In this talk I will present recent work on strong-gravity tidal interactions in black-hole systems. I will discuss how relativistic tidal fields generated by a nearby supermassive black hole can induce resonant phenomena in compact binaries and modify their long-term evolution. Such effects may leave characteristic signatures in the gravitational-wave signals of comparable-mass binaries, potentially accessible to current ground-based detectors.
I will also briefly discuss very asymmetric systems, the so-called extreme mass-ratio inspirals (EMRIs), where a compact object orbits a much more massive black hole. These systems are expected to be key sources for future space-based detectors such as LISA, operating in the millihertz band. I will describe recent results on tidal deformations of rotating black holes and their impact on the dynamics and gravitational-wave emission of EMRIs. Overall, these studies aim to provide new theoretical tools to interpret gravitational-wave observations and to test gravity in the strong-field regime.