Is our vacuum stable?

TL;DR

This paper reviews various aspects of vacuum stability in particle physics and cosmology, including standard model instabilities, models solving the cosmological constant problem, and the potential for universe bifurcation leading to baby universes.

Contribution

It provides a comprehensive review of vacuum stability issues, including new insights into how certain models can ensure stability and the nature of universe bifurcations.

Findings

Standard model vacuum is metastable with a calculable decay rate.

Models solving the cosmological constant problem can stabilize the vacuum.

Bifurcation processes can produce baby universes without catastrophic consequences.

Abstract

The stability of our vacuum is analyzed and several aspects concerning this question are reviewed. 1) In the standard Glashow-Weinberg-Salam (GWS) model we review the instability towards the formation of a bubble of lower energy density and how the rate of such bubble formation process compares with the age of the Universe for the known values of the GWS model. 2) We also review the recent work by one of us (E.I.G) concerning the vacuum instability question in the context of a model that solves the cosmological constant problem. It turns out that in such model the same physics that solves the cosmological constant problem makes the vacuum stable. 3) We review our recent work concerning the instability of elementary particle embedded in our vacuum, towards the formation of an infinite Universe. Such process is not catastrophic. It leads to a "bifurcation type" instability in which our Universe is not eaten by a bubble (instead a baby universe is born). This universe does not replace our Universe rather it disconnects from it (via a wormhole) after formation.