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Title: Anomalous dimensions and non-gaussianity

We analyze the signatures of inflationary models that are coupled to interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the bispectrum, we find a simple scaling behavior determined by operator dimensions, which are constrained by the appropriate unitarity bounds. Specifically, we analyze two simple and calculable classes of examples: conformal field theories (CFTs), and large-N CFTs deformed by relevant time-dependent double-trace operators. Together these two classes of examples exhibit a wide range of scalings and shapes of the bispectrum, including nearly equilateral, orthogonal and local non-Gaussianity in different regimes. Along the way, we compare and contrast the shape and amplitude with previous results on weakly coupled fields coupled to inflation. This signature provides a precision test for strongly coupled sectors coupled to inflation via irrelevant operators suppressed by a high mass scale up to ~ 103 times the inflationary Hubble scale.
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
1063787
Report Number(s):
SLAC-PUB-15334
Journal ID: ISSN 1029-8479; arXiv:1301.2630
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2013; Journal Issue: 10
Publisher:
Springer Berlin
Research Org:
SLAC National Accelerator Laboratory (SLAC)
Sponsoring Org:
US DOE Office of Science (DOE SC);High Energy Physics (HEP);National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS Astrophysics, Phenomenology-HEP, Theory-HEP,HEPTH