Abstract

Contributed Talk - Splinter GWAstronomy

Thursday, 18 September 2025, 14:00

Detection of a nHz-Gravitational Wave Background

Michael Kramer
MPI fuer Radioastronomie

In the summer of 2023, the European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) partnership jointly published evidence for the existence of an nHz-gravitational wave background. These results are supported by similar results presented by the Chinese Pulsar Timing Array, Nanograv and the Parkes Pulsar Timing Array and, more recently, the MeerKAT Pulsar Timing Array. The exceptionally large cadence, the excellent frequency coverage and the unique length of the EPTA data set (thanks to Effelsberg) not only yields the expected Hellings-Downs correlation curve, but also provides unique information on the spectrum of the GW background not accessible by other PTA experiments. This information is used to constrain new physics and dark matter models. The presentation will summarise the experiment, the results and give an outlook on the future.