TH BSM Forum

An Absolute Lower Bound on the Bounce Action

by Masahiro Takimoto

4-3-006 - TH Conference Room (CERN)

4-3-006 - TH Conference Room


Show room on map

The Decay rate of a false vacuum is determined by the minimal action solution of tunnelling field: "bounce”.
In this talk, I focus on models with scalar fields which have canonical kinetic term in N(>2) dimensional Euclidean space, and derive an absolute lower bound on the bounce action. In a case of four dimensional space, I show the bounce action is generically larger than $24/\lambda_{\rm cr}$, where $\lambda_{\rm cr} \equiv {\rm max} [ -4V(\phi) /|\phi|^4] $ with the false vacuum being at $\phi=0$ and $V(0)=0$. I derive this bound on the bounce action without solving the equation of motion explicitly. This simple bound offers a sufficient condition for the stability of a false vacuum, and it can be used as a quick check on the vacuum stability for given models. Our bound can be applied to a broad class of scalar potential with any number of scalar fields. I also briefly discuss a condition for that the bounce action takes a value close to this lower bound. This talk is based on arXiv:1707.01099.

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now