Date and time: Monday, February 15th at 12:00 CET
Speaker: Francesco Costa (UGOE ESR)
Title: Heavy field correction to the primordial power spectrum during inflation
Abstract: Nearly scale-invariant primordial power spectrum is one of the key features of cosmic inflation. To date, no sign of deviations from the simplest single-field inflation models has been observed. On the other hand, realistic models of inflation, meaning particle physics-based models, contain multiple fields other than the inflaton. The presence of heavy fields coupled to the inflaton may alter the predictions of the single-field inflation models.
In this project we consider the effects of heavy fields on the primordial power spectrum, studying a generic model that contains massive scalar and fermion fields coupled to the inflaton.
The radiative corrections introduce the presence in the power spectrum of time-dependent features of two types. One arises from the evolution of the background. The other is an oscillatory feature. The scalar and fermion contributions produce a constant shift and this peculiar oscillatory effects on top of the tree-level primordial power spectrum. Future improvements of CMB measurements may refine our current understanding of the primordial power spectrum and lead to a possible detection of these effects.