On Supersymmetric Flux Solutions of M-theory
  Motivated by the geometric structures of supersymmetric holographic RG-flows, we scan for N=2 AdS_4 solutions in M-theory. One particularly well understood holographic RG flow in M-theory is dual to a mass deformation of the N=8 Chern-Simons theory. We utilize an Ansatz which is a natural generalization of this background in our scan. We find a single new solution with non-trivial internal flux and the topology of S^7. Interestingly, despite our Ansatz being quite general, within our system we rule out solutions with internal flux on more general Sasaki-Einstein seven manifolds. 
Nick Halmagyi, Krzysztof Pilch and Nicholas P. Warner
hep-th