Since the work of Sauter, and Heisenberg, Euler and K\" ockel, it has been understood that
vacuum polarization effects in quantum electrodynamics (QED) predict remarkable new …

We present simple new approximate formulas, for both scalar and spinor QED, for the
number of particles produced from vacuum by a time-dependent electric field, incorporating …

Understanding the emergence of classical behavior from a quantum theory is vital to
establishing the quantum origin for the temperature fluctuations observed in the cosmic …

We consider quantum field theoretic systems subject to a time-dependent perturbation, and
discuss the question of defining a time-dependent particle number not just at asymptotic …

We consider the time evolution of the adiabatic particle number in both time-dependent
electric fields and in de Sitter spaces, and define a superadiabatic particle number in which …

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 …

Since the work of Sauter, and Heisenberg, Euler and Köckel, it has been understood that
vacuum polarization effects in quantum electrodynamics (QED) predict remarkable new …

In time-independent quantum systems, entanglement entropy possesses an inherent scaling
symmetry that the energy of the system does not have. The symmetry also assures that …

A harmonic oscillator with time-dependent mass m (t) and a time-dependent (squared)
frequency ω^ 2 (t) ω 2 (t) occurs in the modelling of several physical systems. It is generally …