Seminario M. Peloso

Il giorno 29 gennaio alle ore 16,30 presso l'aula 300, Marco Peloso (Università di Padova) terra' un seminario dal titolo

Gauge field production from a rolling axion: applications to the early and late universe

Abstract

We will discuss several consequence of the gauge field production from an axion field that is evolving either during the primordial or the current accelerated stage of expansion of the universe.
In the first case, the produced gauge field can source non-Gaussian scalar perturbations, the seeds of Primordial Black- Holes (PBH), and Gravitational Waves (GW) at CMB and at interferometer scales. Motivated by this, we will also discuss strategies for the characterization of the Stochastic GW background of cosmological origin. In the late universe application, we will discuss the possibility that the gauge field production provides an additional friction for the motion of the pseudo-scalar, so that the pseudo-scalar can behave as dark energy also in potentials that are too steep to lead to accelerated expansion in absence of this production.