PIRSA:10030037

Resonant non-Gaussianity

Pajer, E. (2010). Resonant non-Gaussianity. Perimeter Institute. https://pirsa.org/10030037

Pajer, Enrico. Resonant non-Gaussianity. Perimeter Institute, Mar. 16, 2010, https://pirsa.org/10030037 

          @misc{ pirsa_PIRSA:10030037,
            doi = {10.48660/10030037},
            url = {https://pirsa.org/10030037},
            author = {Pajer, Enrico},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Resonant non-Gaussianity},
            publisher = {Perimeter Institute},
            year = {2010},
            month = {mar},
            note = {PIRSA:10030037 see, \url{https://pirsa.org}}
          }

Enrico Pajer

Utrecht University

Talk number
PIRSA:10030037
Collection
Talk Type
Subject
Abstract
Two of the most exciting observables in the cosmic microwave background (CMB) radiation, which could deeply impact our picture of the early universe, are non-Gaussianity and tensor modes. A potential detection of tensor modes can be explained in terms of a model of large field inflation. Theoretical considerations suggest that a symmetry should be invoked in order to protect the flatness of the inflaton potential and hence an axion enjoying a shift symmetry is a natural candidate. As main example, I will present a model of inflation in string theory based on axion monodromy. Non-perturbative effects typically correct the axion potential leading to small sinusoidal modulations on top of an otherwise flat slow roll potential. It can be shown analytically that a resonance between the oscillations of the background and the oscillations of the curvature fluctuations is responsible for the production of an observably large non-Gaussian signal. An explicit expression for the shape of this resonant non-Gaussianity will be presented. There is essentially no overlap between this shape and the local, equilateral, and orthogonal shapes, and in fact resonant non-Gaussianity is not captured by the simplest version of the effective field theory of inflation. Hopefully the analytic expression for resonant non-Gaussianity will be useful to further observationally constrain this class of models.