Holographic Non-Gaussianity
Abstract
We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological curvature perturbations in terms of correlation functions of a holographically dual three-dimensional non-gravitational quantum field theory (QFT). This allows us to compute the primordial bispectrum for a universe which started in a non-geometric holographic phase, using perturbative QFT calculations. Strikingly, for a class of models specified by a three-dimensional super-renormalisable QFT, the primordial bispectrum is of exactly the factorisable equilateral form with f_nl^eq=5/36, irrespective of the details of the dual QFT. A by-product of this investigation is a holographic formula for the three-point function of the trace of the stress-energy tensor along general holographic RG flows, which should have applications outside the remit of this work.
Cite
@article{arxiv.1011.0452,
title = {Holographic Non-Gaussianity},
author = {Paul McFadden and Kostas Skenderis},
journal= {arXiv preprint arXiv:1011.0452},
year = {2011}
}
Comments
42 pages, 2 figs, published version