Nonlocal Effective Field Equations for Quantum Cosmology

TL;DR

This paper develops effective field equations incorporating a running Newton's constant to explore how gravity might strengthen over large distances, predicting accelerated expansion in the universe.

Contribution

It introduces a novel set of effective field equations that include vacuum polarization effects and a running gravitational constant, with implications for cosmological expansion.

Findings

Predicts accelerated power-law expansion at late times

Shows dependence of large-scale behavior on a single parameter

Provides a framework for quantum effects in cosmology

Abstract

The possibility that the strength of gravitational interactions might slowly increase with distance, is explored by formulating a set of effective field equations, which incorporate the gravitational, vacuum-polarization induced, running of Newton's constant $G$. The resulting long distance (or large time) behaviour depends on only one adjustable parameter $\xi$, and the implications for the Robertson-Walker universe are calculated, predicting an accelerated power-law expansion at later times $t \sim \xi \sim 1/H$.