Supersymmetric solutions of non-relativistic 11-dimensional supergravity

Eleven-dimensional supergravity has a non-relativistic variant obtained by taking a limit associated with the M2 brane. Consistency of this non-relativistic supergravity requires constraints. There is one choice of constraints which keeps the maximal amount of supersymmetry transformations, and another which only keeps half. I discuss supersymmetric solutions of this theory, based on limits of the M2 and M5 solutions. These limits involve either a scaling of the number of branes or a smearing in certain directions, and have been argued to produce non-Lorentzian bulk geometries appearing in novel versions of the AdS/CFT correspondence. I show that the scaled solutions are solutions of the maximally supersymmetric version of the non-relativistic supergravity, while the smeared solutions only give solutions of the half-maximally supersymmetric version. I show these solutions are all supersymmetric by solving the Killing spinor equations, and discuss usual and unusual forms of supersymmetry enhancement. I also discuss a simple supersymmetric AdS_3 background, and point out that the BTZ black hole is a solution of non-relativistic 11-dimensional supergravity.