Testing nucleation calculations for strong phase transitions

TL;DR

This paper compares lattice simulations and perturbative calculations of nucleation rates in scalar field theories with first order phase transitions, revealing only qualitative agreement and highlighting the need for further research.

Contribution

The study provides the first lattice simulation of nucleation rates in a scalar field theory with a barrier, testing the accuracy of perturbative methods.

Findings

Lattice results qualitatively differ from perturbative predictions.

Perturbation theory may be insufficient for accurate nucleation rate calculations.

Further lattice studies and higher-order perturbative calculations are needed.

Abstract

Accurate calculations of the nucleation rate $\Gamma$ for first order phase transitions are important for determining their observable consequences in particle physics and cosmology. Perturbative calculations are often used, but they are incomplete and should be tested against fully nonperturbative lattice simulations. We simulate nucleation on the lattice in a scalar field theory with a tree-level barrier, a scenario which should be well described by perturbation theory. Our computation of the nucleation rate, however, only shows qualitative agreement with the perturbative result. This motivates further study of nucleation on the lattice and to higher orders in perturbation theory.