Anomalous dimensions and non-gaussianity

作者：Green Daniel^*; Lewandowski Matthew; Senatore Leonardo; Silverstein Eva; Zaldarriaga Matias

来源：The Journal of High Energy Physics, 2013, 2013(10): 171.

DOI：10.1007/JHEP10(2013)171

• Cosmology of Theories beyond the SM
• Conformal and W Symmetry

We analyze the signatures of inflationary models that are coupled to interacting field theories, a basic class of multi field 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 similar to 10(3) times the inflationary Hubble scale.

• 出版日期2013-10-25