Flat space holography in spin-2 extended dilaton-gravity

TL;DR

This paper develops a new flat space holography framework using an interacting spin-2 gauge theory coupled to 2D dilaton-gravity, revealing an extended asymptotic symmetry group and a novel boundary action.

Contribution

It introduces a spin-2 extension of flat space holography with a BF formulation and derives a new boundary coadjoint action related to warped Schwarzian theory.

Findings

Extended asymptotic symmetry group with central extension.

Derived boundary coadjoint action as spin-2 warped Schwarzian.

Discussed black hole thermodynamics in the model.

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$(S^1)\ltimes C^\infty(S^1)\ltimes$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.