Tunneling potentials to nothing

The catastrophic decay of a spacetime with compact dimensions, via bubbles of nothing (BoNs), is probably a generic phenomenon. BoNs admit a four-dimensional description as singular Coleman–de Luccia bounces of the size modulus field, stabilized by some potential <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>V</a:mi><a:mo stretchy="false">(</a:mo><a:mi>ϕ</a:mi><a:mo stretchy="false">)</a:mo></a:math>. We apply the tunneling potential approach to this 4D description to provide a very simple picture of BoNs. Using it, we identify four different types of BoN, corresponding to different classes of higher-dimensional theories. We also identify 4D theories featuring a new type of quenching of BoN decay, which may be present even for dS vacua, and discuss the viability of embedding such models in a higher-dimensional theory. The present approach allows us to treat in a single framework BoN nucleation and other decay channels, and we study the interplay between the different nonperturbative instabilities comparing their decay rates.