Exact noise kernel for quantum fields in static de Sitter and conformally-flat spacetimes
Abstract
We compute exact expressions of the noise kernel, defined as the expectation value of the symmetrized connected stress energy bitensor, for conformally-invariant scalar fields with respect to the conformal vacuum, valid for an arbitrary separation (timelike, spacelike and null) of points in a class of conformally-flat spacetimes. We derive explicit expressions for the noise kernel evaluated in the static de Sitter coordinates with respect to the Gibbons-Hawking vacuum and analyze the behavior of the noise kernel in the region near the cosmological horizon. We develop a quasi-local expansion near the cosmological horizon and compare it with the exact results. This gives insight into the likely range of validity of the quasi-local approximation expressions for the noise kernel for the conformally invariant scalar field in Schwarzschild spacetime which are given in PHYSICAL REVIEW D{\bf 85}, 044037 (2012).
Cite
@article{arxiv.1301.2501,
title = {Exact noise kernel for quantum fields in static de Sitter and conformally-flat spacetimes},
author = {Jason D. Bates and Hing-Tong Cho and Paul R. Anderson and B. L. Hu},
journal= {arXiv preprint arXiv:1301.2501},
year = {2013}
}
Comments
21 pages, 3 figures