Stretched extra dimensions and bubbles of nothing in a toy model landscape

TL;DR

This paper explores novel geometries in a 6D model, revealing that certain transitions can significantly stretch extra dimensions and that what appears as instability is actually a bubble of nothing, challenging previous assumptions.

Contribution

It introduces simple junction conditions in 6D models to describe unexpected geometries and reinterprets decompactification instability as a bubble of nothing.

Findings

S2 can be significantly stretched in dS4xS2 vacua transitions

Naive decompactification instability is actually a bubble of nothing

New geometrical configurations in a toy 6D landscape

Abstract

Using simple 6D junction conditions, we describe two surprising geometries. First in a case of transitions between dS4xS2 vacua, the S2 can be stretched significantly larger than the vacuum values both before and after the transition. Then we discover that the naive instability to decompactification is actually a bubble of nothing instead.