Speaker
Description
If gauge fields are coupled to an axion field during the inflationary epoch, they can lead to unique observational signatures. However, this system often shows strong backreaction effects, invalidating the standard perturbation theory approach. In this work, we present the first nonlinear lattice simulation of an axion-U(1) system during inflation. We use it to fully characterize the statistics of the comoving curvature perturbation $\zeta$. We use the simulation to characterize the statistics of the comoving curvature perturbation $\zeta$ at the full nonlinear level. Our results invalidate previous bounds coming from overproduction of primordial black holes, allowing for an observable gravitational waves signal at interferometer scales. Our work shows that simulations of this kind can be a crucial tool to understand the phenomenology of the inflationary era and to compute observables from it.
