We analyze various aspects of the recently proposed holographic theories with
general dynamical critical exponent z and hyperscaling violation exponent
θ. We first find the basic constraints on z,θ from the gravity
side, and compute the stress-energy tensor expectation values and scalar
two-point functions. Massive correlators exhibit a nontrivial exponential
behavior at long distances, controlled by θ. At short distance, the
two-point functions become power-law, with a universal form for θ>0.
Next, the calculation of the holographic entanglement entropy reveals the
existence of novel phases which violate the area law. The entropy in these
phases has a behavior that interpolates between that of a Fermi surface and
that exhibited by systems with extensive entanglement entropy. Finally, we
describe microscopic embeddings of some θ=0 metrics into full
string theory models -- these metrics characterize large regions of the
parameter space of Dp-brane metrics for p=3. For instance, the theory of
N D2-branes in IIA supergravity has z=1 and θ=−1/3 over a wide range
of scales, at large gsN.Comment: 35 pages; v2: new references added; v3: proper reference [14] added;
v4: minor clarification