TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.15.1.031
TI  - Late-time correlators and complex geodesics in de Sitter space
PY  - 2023/07/26
UR  - https://www.scipost.org/SciPostPhys.15.1.031
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 15
IS  - 1
SP  - 031
A1  - Aalsma, Lars
AU  - Faruk, Mir Mehedi
AU  - van der Schaar, Jan Pieter
AU  - Visser, Manus R.
AU  - de Witte, Job
AB  - 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.
ER  -

@Article{10.21468/SciPostPhys.15.1.031,
	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={SciPost Phys.},
	volume={15},
	pages={031},
	year={2023},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.15.1.031},
	url={https://scipost.org/10.21468/SciPostPhys.15.1.031},
}