Flat space holography in spin-2 extended dilaton-gravity

Abstract

We present an interacting spin-2 gauge theory coupled to the two-dimensional dilaton-gravity in flat spacetime. The asymptotic symmetry group is enhanced to the central extension of Diff$(S^1)⋉C^{\infty }(S^1)⋉$Vec($S^1$) when the central element of the Heisenberg subgroup is zero (vanishing $U(1)$ level). Using the BF-formulation of the model we derive the corresponding boundary coadjoint action which is the spin-2 extension of the warped Schwarzian theory at vanishing $U(1)$ level. We also discuss the thermodynamics of black holes in this model.

35 pages, v2: minor corrections, text improved, citation updated, v3: introduction revised, clarification added, new subsection 7.3 added, references added