Insane anti-membranes?

The backreactions of anti-branes on a variety of supergravity backgrounds have been shown in a recent series of papers to be riled by some unexplained flux singularities. All of the situations studied so far involve backgrounds with (close to) AdS-asymptotics. It is the purpose of this work to study the backreaction of anti-M2 branes on a background exhibiting a different UV behavior: the so-called A ₈ regular solution of eleven-dimensional supergravity that we consider has "Taub-NUT type" asymptotics. As it turns out, some subleading infrared singularities are inevitable; they cannot be naturally ascribed to the anti-branes backreacting on this background. Moreover, our configuration does not involve smeared branes. This lends further credence to the work of Bena et al. [33] suggesting that the singularities encountered are in no way remnants of smearing that would wash away once brane polarization is taken into account.