Holographic striped phases

We discuss new types of instabilities of D=4 electrically charged AdS-Reissner-Nordstr"om black branes that involve neutral pseudo-scalars. The instabilities spontaneously break translational invariance and are associated with the dual three-dimensional CFTs, at finite temperature and fixed chemical potential with respect to a global abelian symmetry, acquiring striped phases. We show that such instabilities are present for the infinite class of skew-whiffed $Ad{S}_4\times S{E}_7$ solutions of D=11 supergravity, albeit at a lower temperature than the known superfluid instabilities.