# Scale-Invariant Curvature Fluctuations from an Extended Semiclassical Gravity

February 20, 2015

We present an extension of the semiclassical Einstein equations which couples n-point correlation functions of a stochastic Einstein tensor to the n-point functions of the quantum stress-energy tensor. We apply this extension to calculate the quantum fluctuations during an inflationary period, where we take as a model a massive conformally coupled scalar field on a perturbed de Sitter space and describe how a renormalization independent, almost-scale-invariant power spectrum of the scalar metric perturbation is produced. Furthermore, we discuss how this model yields a natural basis for the calculation of non-Gaussianities of the considered metric fluctuations.

open access link
Journal of Mathematical Physics 56, 022303

@article{Pinamonti:2013zba,
author = "Pinamonti, Nicola and Siemssen, Daniel",
title = "{Scale-invariant curvature fluctuations from an extended
semiclassical gravity}",
journal = "J. Math. Phys.",
volume = "56",
year = "2015",
number = "2",
pages = "022303",
doi = "10.1063/1.4908127",
eprint = "1303.3241",
archivePrefix = "arXiv",
primaryClass = "gr-qc",
SLACcitation = "%%CITATION = ARXIV:1303.3241;%%"
}

Keywords:

QFT on curved spacetimes, semiclassical Einstein equation, inflation, cosmology