Seminario Cosmic Inflation from String Axions

Contatto di riferimento: Barbara Simoni

Partecipanti: Dr. Susha Parameswaran (Liverpool University)

Abstract: Inflation, driven by a scalar field slowly rolling down a flat potential, is notoriously plagued by the eta problem, whereby quantum effects generically render the potential too steep.  A very promising way to resolve this problem is if the inflaton is an axion field, whose potential is protected by a perturbative shift symmetry.  However, the canonical models of axion inflation - "Natural Inflation" and "Axion Monodromy" - are now both in tension with observations and difficult to embed in a UV complete theory like string theory.  I will discuss these challenges, and also a way to overcome them, with an inflationary mechanism beyond slow roll that is consistent with observations and that has distinctive signatures