Speaker
Description
Since strong evidence for low-frequency gravitational waves (GWs) was delivered by pulsar-timing array experiments two years ago, its origin and source properties remain unknown. The amplitude of the stochastic GW background may be in mild tension with some black-hole population predictions in the literature, which can be resolved by a combination of a modified galaxy stellar mass function, improved pulsar noise modeling, or even additional contributions from cosmological signals. Anisotropy signatures in the GW background remain undetected and its polarization structure untapped. Resolved signals from individual supermassive black-hole binary systems are still elusive, and targeted GW searches on periodic quasar candidates have not yet yielded compelling evidence. The opportunities for major progress in all these areas remain wide open, and should be accelerated by new facilities projected to come online within the next 5-10 years. I will discuss the direction in which this field is headed, and its connections to LISA through similar source classes and analysis approaches.
