Bubbles created from vacuum fluctuation

TL;DR

This paper demonstrates that bubbles of the form S^2×S^2 can originate from vacuum fluctuations in a De Sitter universe, suggesting a possible foam-like structure in the early universe's inflationary phase.

Contribution

It introduces the concept that vacuum fluctuations can produce S^2×S^2 bubbles in De Sitter space, proposing a new perspective on the early universe's structure.

Findings

Bubbles of S^2×S^2 can be created from vacuum fluctuations.

Such bubbles may form a foam-like structure in the early universe.

The persistence of this foam-like structure during later evolution remains unresolved.

Abstract

We show that the bubbles $S^2\times S^2$can be created from vacuum fluctuation in certain De Sitter universe, so the space-time foam-like structure might really be constructed from bubbles of $S^2\times S^2$ in the very early inflating phase of our universe. But whether such foam-like structure persisted during the later evolution of the universe is a problem unsolved now.