We investigate particle production à la the Schwinger mechanism in an expanding, flat de
Sitter patch as is relevant for the inflationary epoch of our Universe. Defining states and …

Over the years, de Sitter spacetime has been a central focus in studies involving quantum
fields, for its importance in the early and late expansion stages of the universe. While de …

We study the evolution of a quantum scalar field in a toy universe which has three stages of
evolution, viz.,(i) an early (inflationary) de Sitter phase (ii) radiation-dominated phase and …

The problem of finding a vacuum definition for a single quantum field in curved spacetimes
is discussed under a new geometrical perspective. The phase space dynamics of the …

Methods for the numerical evaluation of the Weber parabolic cylinder functions W (a,±x),
which are independent solutions of the inverted harmonic oscillator y ″+(x 2/4–a) y= 0, are …

We investigate the finite-time behavior of pair production from the vacuum by a time-
dependent Sauter pulsed electric field using the spinor quantum electrodynamics (QED). In …

Creation of fermionic particles by a time-dependent electric field and a space-dependent
magnetic field is studied with the Bogoulibov transformation method. Exact analytic solutions …