Expanding Universe and Dynamical Compactification Using Yang-Mills Instantons

TL;DR

This paper investigates how Yang-Mills instantons in extra dimensions can cause our universe to expand and extra dimensions to compactify dynamically, potentially leading to a reheating mechanism through quantum effects.

Contribution

It demonstrates that Yang-Mills instantons in higher dimensions can induce both the expansion of our universe and the compactification of extra dimensions, offering a new mechanism for cosmological evolution.

Findings

Yang-Mills instantons trigger universe expansion.

Instantons induce dynamical compactification of extra dimensions.

Reheating may occur via quantum back-reaction from internal space.

Abstract

We consider an eight-dimensional Einstein-Yang-Mills theory to explore whether Yang-Mills instantons formed in extra dimensions can induce the dynamical instability of our four-dimensional spacetime. We show that the Yang-Mills instantons in extra dimensions can trigger the expansion of our universe in four-dimensional spacetime as well as the dynamical compactification of extra dimensions. We also discuss a possibility to realize a reheating mechanism via the quantum back-reaction from the contracting tiny internal space with a smeared instanton.