Charge-confining gravitational electrovacuum shock wave

In previous publications, we have extensively studied spherically symmetric solutions of gravity coupled to a nonstandard type of nonlinear electrodynamics containing a square-root of the ordinary Maxwell Lagrangian (the latter is known to yield quantum chromodynamic (QCD)-like confinement in a flat spacetime). A class of these solutions describe nonstandard black holes of Reissner-Nordström-(anti-)-de Sitter type with an additional constant radial vacuum electric field, in particular, a non-asymptotically flat Reissner-Nordström-type black hole. Here, we study the ultra-relativistic boost (Lousto-Sanchez extension of Aichelburg-Sexl) limit of the latter and show that, unlike the ordinary Reissner-Nordström case, we obtain a gravitational electrovacuum shock wave as a result of the persistence of the gauge field due to the «square-root» Maxwell Lagrangian term. Next, we show that this gravitational electrovacuum shock wave confines charged test particles (both massive and massless) within a finite distance from its front.