Probing higher spin black holes

Understand

We study the propagation of scalar fields on various backgrounds in three dimensional higher spin gravity.

• Our main emphasis is on obtaining the bulk-boundary propagator, which can be efficiently computed using group theory and higher spin gauge symmetry and from which we can extract scalar two-point functions in the dual CFT.
• As an illustration, we obtain a simple closed form expression for the propagator in a particular spin-3 deformation of AdS_3.
• In the case of higher spin black holes, we prove on general grounds that the propagator respects an imaginary time periodicity consistent with the thermal nature of the black hole; in doing so we make progress in understanding the group exponentiation of the higher spin Lie algebra hs[\lambda], and its center.