Schwinger mechanism revisited

Abstract

In this article, we review recent theoretical works on the Schwinger mechanism of particle production in external electrical fields. Although the non-perturbative Schwinger mechanism is at the center of this discussion, many of the approaches that we discuss can cope with general time and space dependent fields, and therefore also capture the perturbative contributions to particle production.

Electromagnetic currents induced by color fields

“…The initial condition for the quark mode functions which is compatible with the background fields provided by the color glass condensate framework has been derived in Ref. [30].…”

“…In contrast, initial inhomogeneous electric fields can be given by zero gauge field A(0) = 0, and thus they can be consistent with the free initial condition for spinors. In the τ -η coordinates, one can construct the initial condition for the spinors at τ = 0 that is consistent with the evolution of the gauge fields describing a collision of color glass condensates [30]. In this case, the existence of the initial magnetic fields does not cause the inconsistency.…”

“…For generic inhomogeneous gauge fields, we need to resort to lattice-discretized numerical calculations to solve the Dirac equation. In studies of real-time dynamics of fermions on lattice, there have been considerable advances [26,27,28,29,30]. Given these advances, we will give a first-principle description of the quark dynamics under classical gauge fields, and investigate the induction of electromagnetic (EM) current accompanying the quark production.…”

Massive scalar field evolution in de Sitter

“…Also in flat space there are closely related processes: in Schwinger pair creation particles are produced due to a background electric field [44] (for a recent review, see [45]) and in the Unruh effect because of constant acceleration [46]. A crucial conclusion from Hawking radiation is that black holes may be viewed as thermodynamic objects, which is manifested as the relation between the event horizon area and entropy of a black hole [47][48][49][50][51][52].…”

Parametric estimate of the relative photon yields from the glasma and the quark-gluon plasma in heavy-ion collisions

“…The results are however interesting enough to suggest that a more detailed computation of pre-equilibrium photon production rates is desirable. When gluon occupancies are large, this can be achieved by using classical-statistical simulations including dynamical quarks [48][49][50] 3 . First results for the photon production from color background fields in a fixed box geometry are now available [54].…”