Pulsar Timing Arrays: a new window into the gravitational-wave skyConfirmed

by Gabriela Sato-Polito (Institute for Advanced Study)

Wednesday Oct 1, 2025, 2:00 PM → 3:30 PM America/Toronto

PI/2-292 - Time Room (Perimeter Institute for Theoretical Physics)

Pulsar timing arrays (PTAs) consist of a set of regularly monitored millisecond pulsars with extremely stable rotational periods that are used as precise cosmic clocks. The arrival time of pulses can be altered by the passage of gravitational waves (GWs) between them and the Earth, thus serving as a galaxy-wide GW detector. Evidence for low-frequency (~nHz) gravitational waves has recently been reported for the first time across multiple PTA collaborations, opening a new observational window into the Universe. I will discuss how pulsar observations are used to measure GWs, what we are currently learning by mapping the nanohertz GW sky, and what lies ahead following a first detection.