State-Space Based Approach to Particle Creation in Spatially Uniform Electric Fields

TL;DR

This paper applies a state-space formalism to analyze particle creation in uniform electric fields, integrating gauge-invariant approaches to clarify the time evolution and momentum distribution of created particles.

Contribution

It introduces a unified, gauge-invariant framework combining Bogoliubov and tunnelling methods for studying particle creation in electric fields.

Findings

Particles are created with small initial momentum and accelerated by the electric field.

The formalism provides a coherent time-dependent picture of particle creation.

Initial particle states evolve into a combination of vacuum-induced current and initial particle contributions.

Abstract

Our formalism described recently in (Dolby et al, hep-th/0103228) is applied to the study of particle creation in spatially uniform electric fields, concentrating on the cases of a time-invariant electric field and a so-called `adiabatic' electric field. Several problems are resolved by incorporating the `Bogoliubov coefficient' approach and the `tunnelling' approaches into a single consistent, gauge invariant formulation. The value of a time-dependent particle interpretation is demonstrated by presenting a coherent account of the time-development of the particle creation process, in which the particles are created with small momentum (in the frame of the electric field) and are then accelerated by the electric field to make up the `bulge' of created particles predicted by asymptotic calculations. An initial state comprising one particle is also considered, and its evolution is described as being the sum of two contributions: the `sea of current' produced by the evolved vacuum, and the extra current arising from the initial particle state.