Recovering the spacetime metric from a holographic dual
  We review our recent proposal to use certain spatial cross-sections of the boundary at infinity -- light-cone cuts -- to recover the conformal metric in the bulk. We discuss some extensions of this work, including how to obtain the conformal metric near the horizon of a collapsing black hole. We also show how to obtain the conformal factor under certain conditions. 
Netta Engelhardt and Gary T. Horowitz
hep-th gr-qc