Holographic Quantum Critical Transport without Self-Duality

We describe general features of frequency-dependent charge transport near strongly interacting quantum critical points in 2+1 dimensions. The simplest description using the AdS/CFT correspondence leads to a self-dual Einstein-Maxwell theory on AdS4, which fixes the conductivity at a frequency-independent self-dual value. We describe the general structure of higher-derivative corrections to the Einstein-Maxwell theory, and compute their implications for the frequency dependence of the quantumcritical conductivity. We show that physical consistency conditions on the higherderivative terms allow only a limited frequency dependence in the conductivity. The frequency dependence is amenable to a physical interpretation using transport of either particle-like or vortex-like excitations. ar X iv :1 01 0. 04 43 v3 [ he pth ] 1 3 M ar 2 01 1