Princeton University LFTP Seminar
The Nanohertz Gravitational-Wave Sky: Status and Prospects from Pulsar Timing Arrays
Abstract: Pulsar Timing Arrays (PTAs) are galaxy-sized gravitational-wave detectors built from the extraordinarily stable rotation of millisecond pulsars, designed to observe and understand the gravitational-wave universe at nanohertz frequencies. Following the first evidence for nanohertz gravitational waves reported by PTAs in recent years, the field is now moving from detection to characterisation: establishing the origin of the signal, whether a population of supermassive black hole binaries or processes in the early Universe, and searching for the first individually resolvable sources. In this talk I will review the current state of PTA science, drawing on recent results and ongoing work from NANOGrav, the MeerKAT Pulsar Timing Array, and the International Pulsar Timing Array. I will discuss the challenges that now limit our sensitivity, including the modelling of pulsar noise, and outline the prospects for the coming years as data sets lengthen, new telescopes contribute, and regional arrays are combined into a global experiment.