Have pulsar timing arrays detected nano-Hz gravitational waves?
When: Friday, June 26, 2026, 4:00 PM - 5:00 PM
Where: G. O. Jones, Room 610, Mile End
Speaker: Bruce Allen - Max Planck Institute for Gravitational Physics
Title: Have pulsar timing arrays detected nano-Hz gravitational waves?
Abstract: Pulsar timing arrays (PTA) seek to detect nano-Hz frequency
gravitational waves by observing their effects on the arrival times of
pulses from radio pulsars. In June 2023, five different PTA
collaborations published papers based on up to two decades of
observations. Some reported no evidence that they had seen the
effects of nano-Hz gravitational waves. Others reported "compelling
evidence". At the same time, all of the PTAs (apart from the Chinese
PTA) released their full data set. Here, we report on the first
combined analysis of that full public data set. Because this
independent analysis increases both the number of pulsars observed and
the number of data samples per pulsar, it significantly increases the
GW strain sensitivity and the detection confidence. Our paper on this
topic arXiv:2512.08666 is currently under review.
gravitational waves by observing their effects on the arrival times of
pulses from radio pulsars. In June 2023, five different PTA
collaborations published papers based on up to two decades of
observations. Some reported no evidence that they had seen the
effects of nano-Hz gravitational waves. Others reported "compelling
evidence". At the same time, all of the PTAs (apart from the Chinese
PTA) released their full data set. Here, we report on the first
combined analysis of that full public data set. Because this
independent analysis increases both the number of pulsars observed and
the number of data samples per pulsar, it significantly increases the
GW strain sensitivity and the detection confidence. Our paper on this
topic arXiv:2512.08666 is currently under review.