Speaker
Description
For decades a stochastic gravitational wave (GW) background in the nHz band has been theorized from binaries of (super)massive black holes (MBHs). The expected characteristics are broadly consistent with recent measurements from Pulsar Timing Arrays. In this talk, I will present the current state of predictions for MBH binary populations and their GW signatures. I will focus on realistic GW background spectra which can differ notably from the traditional, idealized power-law, and how these simulated spectra compare to current observations. Spectral characterization offers a method of discerning whether the background is indeed produced by binaries, or instead cosmological sources. The characterization of signal anisotropy on the sky, however, is likely the strongest determinant. I will also present models for the expected degree of anisotropy from MBH binaries, which are surprisingly close to current upper limits.
