Gravitational Wave Probes of Physics Beyond Standard Model 4

Session

Astrophysics 2

27 Jun 2025, 11:30

Faculty of Physics, University of Warsaw

Conveners

Astrophysics 2

• Yue Zhao (University of Utah)

19. Gravitational waves from supermassive black holes at pulsar timing arrays

Ville Vaskonen (University of Padova and KBFI)

27/06/2025, 11:30

Inspiralling SMBH binaries constitute a natural explanation of the gravitational wave (GW) background discovered in pulsar timing array (PTA) data. In this talk, I will present a fast semianalytical computation of the expected GW background from SMBH binaries and discuss the SMBH fit to the PTA data that shows evidence of environmental effects or binary eccentricities. I will identify...

25. Pulsar Timing Array Evidence for Self–Interacting Dark Matter in Super-Massive Black-Hole Mergers

Chris Gordon (University of Canterbury (NZ))

27/06/2025, 12:15

Pulsar timing arrays (PTAs) have now revealed a nano-hertz stochastic gravitational-wave background whose amplitude and spectral shape are consistent with a cosmic population of merging super-massive black-hole (SMBH) binaries. Explaining how such binaries bridge the ``final parsec’’ separation before gravitational radiation dominates remains a key challenge. Following the mechanism proposed...

45. Disentangling sources of early matter domination with the gravitaitonal wave spectrum

Graham White (University of Southampton, UK)

27/06/2025, 12:35

An early period of matter domination that suddenly transitions into radiation results in a striking gravitational wave signature. Assuming a given form for the initial power spectrum of curvature fluctuations, one can then do the work to distinguish different sources of early matter domination from features in the spectrum. We first do a model independent analysis where we reduce the features...