Cosmological Sphaleron from Real Tunneling and Its Fate

TL;DR

This paper demonstrates that cosmological sphalerons can originate from real tunneling geometries in Einstein-Yang-Mills systems, and discusses their evolution and pseudo-stability within the universe.

Contribution

It introduces a novel mechanism for producing cosmological sphalerons from real tunneling geometries and analyzes their stability and evolution.

Findings

Sphalerons can be generated from real tunneling geometries.

Sphalerons tend to decay to vacuum or pure gauge configurations.

Sphalerons can be pseudo-stable with lifetimes exceeding the universe's.

Abstract

We show that the cosmological sphaleron of Einstein-Yang-Mills system can be produced from real tunneling geometries. The sphaleron will tend to roll down to the vacuum or pure gauge field configuration, when the universe evolves in the Lorentzian signature region with the sphaleron and the corresponding hypersurface being the initial data for the Yang-Mills field and the universe, respectively. However, we can also show that the sphaleron, although unstable, can be regarded as a pseudo-stable solution because its lifetime is even much greater than those of the universe.