Pulsars, gravitational waves and fuzzy dark matter

Abstract

Pulsars are unique cosmic laboratories with a range of astrophysical applications. Observations of binary pulsar systems provided the first indirect evidence for the existence of gravitational waves. The exceptional rotational stability of millisecond pulsars can be exploited to construct a pulsar timing array as a Galactic-scale detector for nanohertz gravitational waves. In this talk, I will discuss three broadly related research topics. First, I will present a new framework that enables the inference of neutron star population properties (e.g., equation of state and magnetic field evolution) through the synergy of radio observations of Galactic double neutron stars and gravitational-wave measurements of neutron star mergers. Second, I will present some new observational lower and upper limits on the gravitational wave background formed by supermassive binary black holes, which is the primary target for international pulsar timing array efforts. Third, I will present constraints on fuzzy dark matter using Australia's Parkes Pulsar Timing Array.