Speaker: Michalis Agathos (University of Jena)
Title: Probing the nature of gravity with LIGO-Virgo detections
Abstract: The first detection of gravitational waves (GWs) from a coalescing black-hole binary kicked off a new era of gravitational-wave astronomy. Gravitational-wave signals are unique probes of the geometry of black holes and the strong-field dynamics of compact binaries. They also inform us on how gravity is mediated in the weak-field regime, through their propagation at cosmological distances. Thus, with a careful analysis of GW signals, we can probe the nature of gravity, identifying possible violations of GR or placing constraints on alternative theories. In this talk I will give an overview of the current status of such tests with LIGO-Virgo detections and will demonstrate the latest results. I will finally examine the possibility of detecting "GW echoes", a generic feature in the GW phenomenology of exotic compact objects.