Speaker
Fabrizio Rompineve
Description
The recently reported evidence for GWs in PTA datasets leaves the question of whether the signal is astrophysical or coming from the Early Universe. In this talk, I discuss several aspects of cosmological GW backgrounds that can help in addressing this question, and present results of dedicated searches.
In particular, I describe the imprint of the QCD crossover on GW spectra from transient early Universe processes. I then focus on two such sources: large curvature perturbations and cosmic domain walls. I discuss the relevance of complementary constraints on such scenarios for model comparison using PTA data.
