Thermodynamics of higher spin black holes in 3D
Justin R. David, Michael Ferlaino, S. Prem Kumar
TL;DR
This work analyzes the thermodynamics of spin-3 black holes in ${\rm SL}(3,\mathbb{R})\times{\rm SL}(3,\mathbb{R})$ CS theory with a spin-3 chemical potential, revealing four holonomy-allowed branches that interpolate between two AdS$_3$ backgrounds. It establishes that a UV fixed point with ${\cal W}_3^{(2)}\times{\cal W}_3^{(2)}$ symmetry governs the high-temperature regime and that Ward identities of the UV CFT precisely encode the UV/IR thermodynamic map. The authors derive a simple, consistent expression for the grand potential and show how UV variables provide a natural description of the high-$T$ phase, while detailing the geometry (wormhole vs black-hole gauge) and the puzzling features of Branch III. The results generalize to higher ${\rm SL}(N)$ theories and suggest deep connections between holonomy integrability, RG flows in AdS$_3$/CFT$_2$, and higher-spin holography, with potential checks via UV/IR Ward identities and free-field realizations.
Abstract
We examine the thermodynamic properties of recently constructed black hole solutions in SL(3,R) x SL(3,R) Chern-Simons theory in the presence of a chemical potential for spin-3 charge, which acts as an irrelevant deformation of the dual CFT with W_3 x W_3 symmetry. The smoothness or holonomy conditions admit four branches of solutions describing a flow between two AdS_3 backgrounds corresponding to two different CFTs. The dominant branch at low temperatures, connected to the BTZ black hole, merges smoothly with a thermodynamically unstable branch and disappears at higher temperatures. We confirm that the UV region of the flow satisfies the Ward identities of a CFT with W_3^(2) x W_3^(2) symmetry deformed by a spin-3/2 current. This allows to identify the precise map between UV and IR thermodynamic variables. We find that the high temperature regime is dominated by a black hole branch whose thermodynamics can only be consistently inferred with reference to this W_3^(2) x W_3^(2) CFT.
