Pulsar Timing Arrays: A new window into the gravitational wave Universe

In this talk, I will briefly highlight the recent breakthrough results from Pulsar Timing Arrays (PTAs) that showed evidence for the presence of a nanohertz-frequency gravitational wave background (GWB). I will describe the insights into our Universe that come from this discovery and the questions that still remain to be answered. I will then focus on how all the international PTAs, both individually and through the International Pulsar Timing Array (IPTA) collaboration, are preparing to improve our measurements of the GWB and search for other nanohertz-frequency gravitational wave signals.