🔹 Title: Pulsar Timing Arrays: searching for low-frequency gravitational waves using the most precise cosmic clock

🔹 Speaker: Marta Burgay (INAF-OAC)

🔹 Abstract: Pulsar Timing Arrays (PTA) use a Galactic-scale interferometer made of selected millisecond pulsars to detect low-frequency gravitational waves (GW) generated by coalescing supermassive black-hole binaries. The ensemble of low-frequency GWs introduces specific perturbations in the trains of radio pulses from all pulsars that are spatially correlated. This common correlated signal is the main target of PTA searches. Its detection will open a new window in the GW spectrum, and a new way to study supermassive black hole binaries.  Recently, the European PTA (EPTA) and other worldwide PTA collaborations have detected a tantalising signal that appears to be common among all the pulsars, albeit, so far, uncorrelated. This has prompted additional, coordinated efforts to produce the most refined and sensitive PTA datasets to date, as well as new algorithms and statistical approaches, to tackle the real nature of this signal and achieve the first, low-frequency GW detection. In this talk, I will review the PTA methods and most recent results.