Inertial mechanism: dynamical mass as a source of particle creation

TL;DR

This paper develops a kinetic theory for vacuum particle creation driven by an inertial mechanism, applicable to various fields, and explores its implications in cosmology and scalar field models.

Contribution

It introduces a nonperturbative dynamical approach to vacuum particle creation with a kinetic theory framework for different fields, linking quantum field theory with cosmological phenomena.

Findings

Derived non-Markovian kinetic equations for scalar, spinor, and vector fields.

Applied the theory to cosmological models and photon density in CMB.

Analyzed conditions for tachyonic modes and vacuum state definitions.

Abstract

A kinetic theory of vacuum particle creation under the action of an inertial mechanism is constructed within a nonpertrubative dynamical approach. At the semi-phenomenological level, the inertial mechanism corresponds to quantum field theory with a time-dependent mass. At the microscopic level, such a dependence may be caused by different reasons: The non-stationary Higgs mechanism, the influence of a mean field or condensate, the presence of the conformal multiplier in the scalar-tensor gravitation theory etc. In what follows, a kinetic theory in the collisionless approximation is developed for scalar, spinor and massive vector fields in the framework of the oscillator representation, which is an effective tool for transition to the quasiparticle description and for derivation of non-Markovian kinetic equations. Properties of these equations and relevant observables (particle number and energy densities, pressure) are studied. The developed theory is applied here to describe the vacuum matter creation in conformal cosmological models and discuss the problem of the observed number density of photons in the cosmic microwave background radiation. As other example, the self-consistent evolution of scalar fields with non-monotonic self-interaction potentials (the W-potential and Witten - Di Vecchia - Veneziano model) is considered. In particular, conditions for appearance of tachyonic modes and a problem of the relevant definition of a vacuum state are considered.