What do non-relativistic CFTs tell us about Lifshitz spacetimes?

Understand

We study the reconstructability of (d+2)-dimensional bulk spacetime from (d+1)-dimensional boundary data, particularly concentrating on backgrounds which break (d+1)-dimensional Lorentz invariance.

• For a large class of such spacetimes, there exist null geodesics which do not reach the boundary.
• Therefore classically we expect some information is trapped in the bulk and thus invisible at the boundary.
• We show that this classical intuition correctly predicts the quantum situation: whenever there are null geodesics which do not reach the boundary, there are also "trapped scalar modes" whose boundary imprint is exponentially suppressed.