Real-time dynamics of false vacuum decay

TL;DR

This paper studies the real-time decay of false vacuum states in a relativistic scalar field using non-perturbative quantum field theory methods, comparing quantum and classical approaches, and revealing time-dependent decay rates and quantum effects.

Contribution

It introduces a real-time, non-perturbative framework for analyzing false vacuum decay, incorporating quantum corrections and comparing them with classical simulations.

Findings

Decay rates are comparable to Euclidean bounce results.

Decay rates are time-dependent during the transition.

Quantum corrections can induce transitions absent in classical simulations.

Abstract

We investigate false vacuum decay of a relativistic scalar field initialized in the metastable minimum of an asymmetric double-well potential. The transition to the true ground state is a well-defined initial-value problem in real time, which can be formulated in nonequilibrium quantum field theory on a closed time path. We employ the non-perturbative framework of the two-particle irreducible (2PI) quantum effective action at next-to-leading order in a large-N expansion. We also compare to classical-statistical field theory simulations on a lattice in the high-temperature regime. By this, we demonstrate that the real-time decay rates are comparable to those obtained from the conventional Euclidean (bounce) approach. In general, we find that the decay rates are time dependent. For a more comprehensive description of the dynamics, we extract a time-dependent effective potential, which becomes convex during the nonequilibrium transition process. By solving the quantum evolution equations for the one- and two-point correlation functions for vacuum initial conditions, we demonstrate that quantum corrections can lead to transitions that are not captured by classical-statistical approximations.