Nonperturbative late time asymptotics for heat kernel in gravity theory

TL;DR

This paper extends the understanding of the late time behavior of the heat kernel in curved spacetimes, revealing nonlocal effects that could influence long-distance modifications of gravity and offer insights into the cosmological constant problem.

Contribution

It generalizes nonperturbative late time heat kernel asymptotics to curved spacetimes, highlighting nonlocal terms relevant for gravity modifications and cosmological constant issues.

Findings

Heat kernel trace asymptotics dominated by two terms.

One term is a covariant flat-space generalization.

Another term involves Gibbons-Hawking integral.

Abstract

Recently proposed nonlocal and nonperturbative late time behavior of the heat kernel is generalized to curved spacetimes. Heat kernel trace asymptotics is dominated by two terms one of which represents a trivial covariantization of the flat-space result and another one is given by the Gibbons-Hawking integral over asymptotically-flat infinity. Nonlocal terms of the effective action generated by this asymptotics might underly long- distance modifications of the Einstein theory motivated by the cosmological constant problem. New mechanisms of the cosmological constant induced by infrared effects of matter and graviton loops are briefly discussed.