📝 SummarXiv

Abstract

We employ a self consistent framework to study the backreaction effects of particle creation in the coupled semiclassical dynamics of a quantum complex scalar field and a classical electric field in both (1 + 1) and (1 + 3) dimensional Minkowski and de Sitter spacetimes. Using a general Gaussian state formalism in the Schrodinger picture, we solve the resulting nonlinear equations with Gaussian initial data, obtaining a self consistent semiclassical evolution that incorporates nonperturbative backreaction. We compute the time-dependent instantaneous particle content, current density, and electric field, defined through instantaneous eigenstates of the field modes. Comparing scenarios with and without backreaction, we find that backreaction strongly modifies the electric field and current, producing immediate plasma like oscillations and driving pronounced oscillations in the instantaneous mode occupations through nonadiabatic squeezing and quantum interference. These oscillations do not imply additional irreversible particle production the time averaged particle number remains essentially constant but they reveal the rich nonperturbative real-time dynamics captured by our self-consistent semiclassical approach across dimensions and in both Minkowski and de Sitter backgrounds.