Super Cosmic Variance with Two Light Scalars

by Anne-Sylvie Deutsch (Pennsylvania State University)

Wednesday 25 May 2016, 14:00 → 15:00 Europe/Brussels

E/3rd floor-E.349 - Seminar room (E.349) (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

***PLEASE NOTE THE UNUSUAL STARTING TIME*** For inflation to solve the shortcomings of the Λ-CDM model, one need a minimum number of e-folds of about N~60. However, there is no upper bound on N, and therefore the inflationary volume might be much bigger than our observable Hubble patch. The local, observed cosmological parameters can hence be significantly different than those in the large volume. In order to understand how local and global statistics can differ, we examine the coupling between long and short density perturbation modes in the context of a two-field inflationary model. In particular, we compute the influence of long modes on correlation functions of short modes. From the power spectrum, we derive the observed spectral index and tensor-to-scalar ratio, and give an estimation of the amplitude of the bias due to long-short modes coupling. We also study the squeezed limit of the bispectrum, for which the scaling is related to the mass of the extra field.