Comments on critical electric and magnetic fields from holography

Abstract

Abstract:We discuss some aspects of critical electric and magnetic fields in a field theory with holographic dual description. We extend the analysis of [1], which finds a critical electric field at which the Schwinger pair production barrier drops to zero, to the case of magnetic fields. We first find that, unlike ordinary weakly coupled theories, the magnetic field is not subject to any perturbative instability originating from the presence of a tachyonic ground state in the W-boson spectrum. This follows from the large value of the 't Hooft coupling λ, which prevents the Zeeman interaction term to overcome the particle mass at high B. Consequently, we study the next possible B-field instability, i.e. monopole pair production, which is the S-dual version of the Schwinger effect. Also in this case a critical magnetic field is expected when the tunneling barrier drops to zero. These Schwinger-type criticalities are the holographic duals, in the bulk, to the fields E or B reaching the tension of F1 or D1 strings respectively. We then discuss how this effect is modified when electric and magnetic fields are present simultaneously and dyonic states in the spectrum can be pair produced by a generic E − B background. Finally, we analyze finite temperature effects on Schwinger criticalities, i.e. in the AdS-Schwarzshild black hole background.

Electromagnetic instability in holographic QCD

“…Based on [6,7], the holographic Schwinger effect were calculated in various systems [8][9][10][11][12][13][14][15]. On the other hand, two of the present authors obtained the vacuum decay rate, which can be identified as the creation rate of quark-antiquark pairs, in N = 2 supersymmetric QCD(SQCD) by using a different method [16] in AdS/CFT correspondence: the imaginary part of the probe D-brane action.…”

Schwinger mechanism revisited

“…[166], and some of the many works where holographic (e.g. based on the AdS/CFT correspondence) setups were considered in order to investigate particle production by external fields in the strong coupling regime [167][168][169][170][171][172][173][174][175][176]. Let us also finally mention another recent review on the Schwinger mechanism more focused on the backreaction and applications in astrophysics [177], as well as some works on the closely related question of pair creation in a curved space-time [178][179][180][181][182][183].…”

Notes on holographic Schwinger effect

“…This value coincides with the critical value of the Dirac-Born-Infeld (DBI) action of the probe D3-brane with an electric field turned on. This proposal is generalized in other cases [10][11][12][13]. The key technique of the proposal is similar to that of the holographic calculation of the VEV of a circular Wilson loop [14][15][16].…”