Speaker
Valerie Domcke
Description
Scalar perturbations source GWs at second order in cosmological perturbation theory. GW observations thus set bounds on (or give hints for) an enhanced scalar power spectrum at small scales. I will discuss the status of constraints on the scalar power spectrum set by PTAs as well as from primordial black hole (PBH) production, demonstrating that the latter seriously challenge an explanation of the recent PTA results as scalar-induced GWs.
