Extending the non-singular hyperscaling violating spacetimes

Abstract

Lifshitz and hyperscaling violating geometries, which provide a holographic description of non-relativistic field theories, generically have a singularity in the infrared region of the geometry, where tidal forces for freely falling observers diverge, but there is a special class of hyperscaling violating geometries where this tidal force divergence does not occur. We explicitly construct a smooth extension of the spacetime in this case, and explore the structure of the spacetime. We argue that the extension involves an enlargement of the field theory Hilbert space, as in AdS2. We also consider the behaviour of finite-energy excitations of the spacetime at the horizon, arguing that they will have some divergence there.