Towards a bulk description of higher spin SYK
Hernán A. González, Daniel Grumiller, Jakob Salzer
TL;DR
The paper develops a bulk-to-boundary framework for generalized SYK/JT holography by formulating two-dimensional dilaton gravity as a non-abelian BF theory with SL(2, R) as a gravity subsector and extending it with Yang–Mills and higher-spin symmetries. It derives generalized Schwarzian boundary actions via two routes: (i) an on-shell action with boundary terms respecting symmetries, and (ii) a Lee–Wald–Zoupas-inspired symplectic analysis that yields group-manifold boundary actions and higher-spin Schwarzian analogues. The work provides a unified description of entropy and one-loop corrections in these extended theories, showing that spin-2 dominates at very low temperatures while higher spins contribute through Casimir-related terms and logarithmic corrections, and it builds a holographic dictionary linking bulk data to SYK-like couplings and temperature. These results broaden the landscape of SYK-like holography, offering a structured route to incorporate Yang–Mills and higher-spin dynamics into the low-energy, Schwarzian-dominated regime and setting the stage for further explorations of W-algebras in two-dimensional holography.
Abstract
We consider on the bulk side extensions of the Sachdev--Ye--Kitaev (SYK) model to Yang--Mills and higher spins. To this end we study generalizations of the Jackiw--Teitelboim (JT) model in the BF formulation. Our main goal is to obtain generalizations of the Schwarzian action, which we achieve in two ways: by considering the on-shell action supplemented by suitable boundary terms compatible with all symmetries, and by applying the Lee--Wald--Zoupas formalism to analyze the symplectic structure of dilaton gravity. We conclude with a discussion of the entropy (including log-corrections from higher spins) and a holographic dictionary for the generalized SYK/JT correspondence.
