Singularities in Hyperscaling Violating Spacetimes

Understand

We examine spacetimes which generalize Lifshitz scaling to allow hyperscaling violation invariance (i.e.

• a constant conformal transformation) for the types of singularities frequently found in the Lifshitz case.
• We find that most of these spacetimes suffer either from a traditional naked curvature singularity or a null curvature singularity robust against stringy higher derivative corrections.
• We do find a one-parameter family that evades these issues but this family requires exotic matter, in particular involving a negative energy density that may not be interpreted as due to a cosmological constant.