Non-Gaussianities from Multi-Field Inflation

          @misc{ pirsa_PIRSA:06120020,
            doi = {10.48660/06120020},
            url = {https://pirsa.org/06120020},
            author = {Battefeld, Thorsten},
            keywords = {Cosmology},
            language = {en},
            title = {Non-Gaussianities from Multi-Field Inflation},
            publisher = {Perimeter Institute},
            year = {2006},
            month = {dec},
            note = {PIRSA:06120020 see, \url{https://pirsa.org}}
          }
          

Abstract

Non-Gaussianities are a generic prediction of multi-field inflationary models and within reach of upcoming experiments. After reviewing current observational limits and the physical origin of a non-zero three point correlation function, I will discuss the possibility of detectable non-Gaussian signatures in a certain class of multi-field inflationary models, upon which assisted inflation/N-flation lies. Using the delta-N formalism within the slow roll approximation and focusing on N-flation (quadratic potentials without cross-coupling), we will see that said signatures are suppressed as the number of e-foldings grows, and that this suppression is increased in models with a broad spectrum of masses. We thus conclude that the production of a large non-Gaussian signal in models of this type is very unlikely.