R-symmetries, anomalies and non-invertible defects from non-BPS branes

Abstract: We propose a holographic realization of symmetry operators for symmetries associated to isometries in terms of non-BPS Kaluza-Klein monopoles. Their existence is supported by dualities, and their action can be inferred by consistency with well-known String Theory constructions. We use our proposal to describe the $U(1)$ superconformal R-symmetry of the Klebanov-Witten 4d $\mathcal{N}=1$ theory dual to Type IIB String Theory on $AdS_5\times T^{1,1}$. We precisely reproduce the expectations from field theory, including the 't Hooft self-anomaly of the R-symmetry and the mixed 't Hooft anomaly with the baryonic symmetry. For a choice of boundary conditions, the R-symmetry becomes non-invertible and the worldvolume action for the non-BPS Kaluza-Klein monopole precisely accounts for this.