KICP Colloquium: Kai Schmitz (University of Münster)

3:30–4:30 pm ERC 161

Host: Dan Hooper

Kai Schmitz (University of Münster) "New Physics at the Pulsar Timing Array Frontier"

Pulsar Timing Array (PTA) collaborations around the globe recently announced compelling evidence for a gravitational-wave background (GWB) at nanohertz frequencies. This breakthrough achievement has important implications for astrophysics, as the GWB signal, if genuine, is likely to originate from a cosmic population of supermassive black holes orbiting each other at the centers of galaxies. At the same time, PTA observations are also of great interest to the high-energy physics community. As I will illustrate in this talk, PTA data represent a new type of precision data that may contain signatures of new particle or gravitational physics, including signatures of (1) new physics in the early Universe, (2) dark matter in the Milky Way, (3) dark-matter halos around supermassive black-hole binaries, and (4) modified gravity. In my talk, I will give an overview of these searches for new physics at the PTA frontier and highlight several scenarios that underline the relevance of PTA observations for fundamental problems such as cosmic inflation, the matter-antimatter asymmetry of the Universe, and dark matter. Finally, I will conclude with a brief outlook on the future of the field and sketch possible pathways to the discovery of new physics in PTA data in the coming years and decades.

Event Type


Mar 27