Unexpected discoveries in gravitational-wave astrophysics

Via Zoom

Since the first discoveries in 2015, gravitational-wave and multi-messenger observations yielded a number of “surprises”. We have detected more and heavier black holes than previously anticipated; multi-messenger emission from neutron star merger GW170817 showed a structured high-energy outflow and produced a multi-component kilonova; additional messengers, such as heavy elements detected on Earth helped us identify nearby, impactful events. With the current publicly announced detection rate of about one per week, the latest observing period of LIGO delivered several surprises, and moved the field towards precision astrophysics. I will review several of the new interesting directions in gravitational-wave and multi-messenger observations that began only recently and promise to further enrich this field as the rate of detections will grow twentyfold in the next five years.