Non-Gaussianity: Asymmetry and Squeezed Limits

Series: 
The London Relativity and Cosmology Seminar
Speaker: 
Zac Kenton (QMUL)
Date: 
October 7th, 2015 at 16:30
Room: 
See Talk Details
Abstract: 

In this talk I'll present work based on primordial non-Gaussianities arising in multi-field inflation using the delta-N formalism. 
In the first part of this talk I'll describe our paper 'Generating the CMB Power Asymmetry with g_NL' http://arxiv.org/abs/1504.05736, in which we show that using a higher order term in the delta-N expansion can give the observed power asymmetry without requiring a large value of f_NL, requiring instead a non-zero value of g_NL.  
In the second part of the talk I'll present our calculation of the squeezed limit of the bispectrum produced by inflation with multiple light fields, http://arxiv.org/abs/1507.08629. I'll show analytic results for the bispectrum of the primordial curvature perturbation and the spectral index of the halo bias, an important observational probe of the squeezed limit of the primordial bispectrum. I'll compare our new results to those existing in the literature by considering the example of a curvaton model, finding a 20% correction to the theoretical prediction for observable parameters for squeezings relevant to future experiments. If there's time I'll also present some preliminary results on the trispectrum too. - G. O. Jones 510