Institute for Advanced Study/Princeton University Gravitational Waves Meeting

Gravitational-wave astronomy has already transformed our understanding of the Universe. With current detectors LIGO, Virgo, and KAGRA, we have witnessed the mergers of black holes and neutron stars, uncovered unexpected features of their populations, and opened new windows on fundamental physics and cosmology. Yet this is only the beginning. The next generation of detectors — Cosmic Explorer in the US and Einstein Telescope in Europe — will deliver a dramatic leap in sensitivity, opening access to sources across the entire Universe. In this talk, I will discuss how these observatories will revolutionize our view of black hole formation and cosmic evolution. I will focus on two frontiers: the detection and characterization of intermediate-mass black holes — the long-sought missing link between stellar and supermassive black holes — and the study of stochastic gravitational-wave backgrounds, the diffuse hum produced by countless astrophysical and cosmological sources. I will highlight some of the key theoretical and data-analysis challenges, from modelling the formation channels and population properties of intermediate-mass black holes to disentangling the multiple components of the stochastic background. Finally, I will present recent progress toward addressing these challenges and realizing the full scientific potential of next-generation observatories.