Quantum Weyl Invariance and Cosmology

TL;DR

This paper develops a Weyl invariant formalism for cosmological equations, incorporating quantum effects and anomalies, leading to modified Einstein equations with implications for dark energy and the cosmological constant problem.

Contribution

It introduces a quantum-modified framework for cosmology based on Weyl invariance, addressing long-distance quantum effects and their impact on cosmological evolution.

Findings

Nonlocal energy-momentum tensor near two dimensions

Slowly decaying vacuum energy in the model

Quantum modifications to Einstein equations in four dimensions

Abstract

Equations for cosmological evolution are formulated in a Weyl invariant formalism to take into account possible Weyl anomalies. Near two dimensions, the renormalized cosmological term leads to a nonlocal energy-momentum tensor and a slowly decaying vacuum energy. A natural generalization to four dimensions implies a quantum modification of Einstein field equations at long distances. It offers a new perspective on time-dependence of couplings and naturalness with potentially far-reaching consequences for the cosmological constant problem, inflation, and dark energy.