Quantum group origins of edge states in double-scaled SYK

Abstract

Double-scaled SYK (DSSYK) is known to have an underlying quantum group theoretical description. We precisely pinpoint the quantum group structure, improving upon earlier work in the literature. This allows us to utilize this framework for bulk gravitational applications. We explain bulk discretization in DSSYK from the underlying irreducibility of the representations. We derive trumpet and brane amplitudes using character insertions of the quantum group, simplifying earlier calculations. Most importantly, we factorize the bulk Hilbert space dual to DSSYK in the quantum group description using a complete set of edge degrees of freedom living at a bulk entangling surface. An analogous treatment for $\mathcal{N}=1$ DSSYK is provided in the same quantum group theoretical framework.