Observables and Microscopic Entropy of Higher Spin Black Holes
Geoffrey Compère, Juan I. Jottar, Wei Song
TL;DR
The paper develops a unified, gauge-invariant framework for higher spin black hole thermodynamics in AdS3, introducing tilde (tilded) conserved charges and conjugate sources, a canonical bulk entropy, and a bulk-boundary dictionary aligned with the asymptotic W-symmetries. By analyzing spin-2 and spin-3 cases and generalizing to sl(N,R) and hs[λ], it shows that canonical observables reproduce CFT counting when expressed in tilde variables, resolving discrepancies with holomorphic formalisms. The authors demonstrate that deformed CFTs retain their $ ext{W}$-symmetry structure and provide explicit holonomy-based conditions to define vacua and ensure thermodynamic consistency. The framework yields a consistent entropy and first-law relationship via a Legendre transform of the free energy and matches CFT partition functions across the bulk-boundary dictionary, with tilded variables providing a universal map across embeddings and algebras.
Abstract
In the context of recently proposed holographic dualities between higher spin theories in AdS3 and 1+1-dimensional CFTs with W-symmetry algebras, we revisit the definition of higher spin black hole thermodynamics and the dictionary between bulk fields and dual CFT operators. We build a canonical formalism based on three ingredients: a gauge-invariant definition of conserved charges and chemical potentials in the presence of higher spin black holes, a canonical definition of entropy in the bulk, and a bulk-to-boundary dictionary aligned with the asymptotic symmetry algebra. We show that our canonical formalism shares the same formal structure as the so-called holomorphic formalism, but differs in the definition of charges and chemical potentials and in the bulk-to-boundary dictionary. Most importantly, we show that it admits a consistent CFT interpretation. We discuss the spin-2 and spin-3 cases in detail and generalize our construction to theories based on the hs[λ] algebra, and on the sl(N,R) algebra for any choice of sl(2,R) embedding.
