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...
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...
