Late-Time Correlators and Complex Geodesics in de Sitter Space
Abstract
We study two-point correlation functions of a massive free scalar field in de Sitter space using the heat kernel formalism. Focusing on two operators in conjugate static patches we derive a geodesic approximation to the two-point correlator valid for large mass and at late times. This expression involves a sum over two complex conjugate geodesics that correctly reproduces the large-mass, late-time limit of the exact two-point function in the Bunch-Davies vacuum. The exponential decay of the late-time correlator is associated to the timelike part of the complex geodesics. We emphasize that the late-time exponential decay is in tension with the finite maximal entropy of empty de Sitter space, and we briefly discuss how non-perturbative corrections might resolve this paradox.
Cite
@article{arxiv.2212.01394,
title = {Late-Time Correlators and Complex Geodesics in de Sitter Space},
author = {Lars Aalsma and Mir Mehedi Faruk and Jan Pieter van der Schaar and Manus Visser and Job de Witte},
journal= {arXiv preprint arXiv:2212.01394},
year = {2023}
}
Comments
18 pages, 8 figures. v2: 19 pages + 2 pages appendices, 11 figures. Matches published version