Towards Next-Generation Gravitational-Wave Detectors: Intermediate-Mass Black Holes and Stochastic Backgrounds

Current gravitational-wave observatories — LIGO, Virgo, and KAGRA — have made phenomenal new discoveries that are already making waves in a range of fields from fundamental physics to cosmology. Yet the era of gravitational-wave astronomy is still at its dawn. The next generation of ground-based detectors — Cosmic Explorer in the US and Einstein Telescope in Europe — will bring a dramatic increase in sensitivity, enabling observations across the entire Universe and a comprehensive census of gravitational-wave sources throughout cosmic history. In this talk, I will highlight the transformative potential of these detectors in two key areas: the detection and characterization of intermediate-mass black holes and the study of stochastic gravitational-wave backgrounds. I will discuss some of the main theoretical and data-analysis challenges involved — from modeling 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.