- #1

- 131

- 94

- TL;DR Summary
- I'd like to have a better physical picture of metastable vacuum decay

Consider the decay in a quantum field theory from a metastable vacuum to the "true" vacuum.

Here's i my understanding:

1. For a scalar field potential U(\phi), the transition amplitude is finite per unit volume for a finite energy splitting between the 2 classical minima of the potential. This implies that there is a finite probability per time that some (finite region) subset of the spacetime decays into the true vacuum.

This transition amplitude can be computed by computing the action in euclidean time of a spherically symmetric instanton solution.

Why is this process called bubble nucleation? It is also said that it is related to phase transitions, but I fail to see the connection. Here one is talking about a tunneling amplitude to transition from one (false) vacuum to the real one.

Here's i my understanding:

1. For a scalar field potential U(\phi), the transition amplitude is finite per unit volume for a finite energy splitting between the 2 classical minima of the potential. This implies that there is a finite probability per time that some (finite region) subset of the spacetime decays into the true vacuum.

This transition amplitude can be computed by computing the action in euclidean time of a spherically symmetric instanton solution.

**My question**:Why is this process called bubble nucleation? It is also said that it is related to phase transitions, but I fail to see the connection. Here one is talking about a tunneling amplitude to transition from one (false) vacuum to the real one.

Last edited: