Non-Abelian Symmetry Operators from Hanging Branes in $AdS_5 \times S^5$

Abstract

We investigate the holographic realization of topological operators for continuous non-Abelian symmetries in quantum field theories. As a concrete case study, we focus on Type IIB string theory on $AdS_5 \times S^5$ which admits an $SO(6)$ isometry, dual to the R-symmetry in 4d $N=4$ super Yang-Mills theory. We argue that symmetry operators for continuous symmetries are generally realized by bound states of D5-branes and KK monopoles hanging from the conformal boundary. Together they account for the contributions to the Gauss' law constraints from the self-dual 5-form flux and the Einstein-Hilbert term respectively. We also demonstrate how the D5-KK bound state measures the representation of the endpoint of Wilson lines constructed by D3-branes.