Dr. Valerio De Luca is currently a postdoctoral fellow at Johns Hopkins University, having previously spent three years as a postdoc at Penn.
Title: "Strong-gravity observables in black hole physics"
Abstract: The physics of black holes in strong gravity admits a rich set of observables, whose properties are often deeply constrained by the symmetry structure of the underlying theory. We explore three key observables across different stages of binary evolution and signal propagation: tidal Love numbers, quasinormal modes, and gravitational lensing. During the inspiral, tidal Love numbers characterize the conservative response of compact objects to external tidal fields. We revisit their vanishing for black holes in General Relativity from a symmetry-based perspective, drawing an analogy with the behaviour of supersonic acoustic flows in analogue gravity models. In the ringdown, quasinormal modes encode the characteristic oscillations of perturbed black holes. We discuss the isospectrality between the two parity sectors and trace its origin to a gravitational electric-magnetic duality in the eikonal plane-wave limit. Finally, gravitational lensing imprints frequency-dependent amplitude and phase modulations on propagating gravitational-wave signals. We show how the standard lensing formalism admits a natural reinterpretation within the framework of scattering theory, establishing a direct correspondence between the lensing amplification factor and the scattering amplitude of waves in curved spacetime.
