Detecting nano-Hertz gravitational waves with Pulsar Timing Arrays

by Bruce Allen

Wednesday 22 May 2024, 13:00 → 14:00 Europe/Berlin

A.1.01/03 - Alps (New)

Around the world, several groups are working to detect a stochastic background of very low frequency gravitational waves using "pulsar timing arrays".  Such gravitational waves are generated by orbiting pairs of extremely massive black holes at cosmological distances from Earth.  The "detector" operates at a Galactic-scale, by exploiting radio pulsars (very stable rapidly-spinning neutron stars) as high precision clocks.  I'll explain how these detectors operate -- the gravitational waves leave detectable imprints on the radio pulses -- and review the current state of the field and its prospects. 

I'll also describe some recent work (arXiv 2205.05637, 2208.07230, 2308.05847, 2401.14329, 2404.05677) on properties of the "Hellings and Downs correlation". This pattern of pulsar timing correlations is the "smoking gun" that should reveal the presence of gravitational waves.