Bispectrum signatures of modifications to the inflationary vacuum

          @misc{ pirsa_PIRSA:09050051,
            doi = {10.48660/09050051},
            url = {https://pirsa.org/09050051},
            author = {van der Schaar, Jan Pieter},
            keywords = {Cosmology},
            language = {en},
            title = {Bispectrum signatures of modifications to the inflationary vacuum},
            publisher = {Perimeter Institute},
            year = {2009},
            month = {may},
            note = {PIRSA:09050051 see, \url{https://pirsa.org}}
          }
          

Abstract

Modifications of the initial-state of the inflaton field can induce a departure from Gaussianity and leave a testable imprint on the higher order correlations of the CMB and large scale structures in the Universe. I will discuss general vacuum state modifications in the case of a canonical single-field action, after adding a dimension 8 higher order derivative term, and DBI models of inflation. Observed bounds on local and equilateral non-Gaussianities, even though they correspond to template shapes that are far from optimal, can lead to constraints that are already competing to those derived from the power spectrum alone, due to enhancement effects. We emphasize that the construction and application of especially adapted templates could lead to significant improvements in the CMB bispectrum constraints on modified initial states.