Symmetries play a fundamental role in the study of Quantum Field Theories (QFTs). They provide selection rules, constrain the dynamics of QFTs, and, through anomalies, offer a method to test IR or UV dualities among different QFTs. It is then crucial to understand the symmetries that a theory can enjoy. This recently motivated the study of generalized global symmetries and the description of discrete symmetries through the symmetry Topological Field Theory (symTFT), which separates the symmetry structure from the field theory dynamics. Holography represents a natural laboratory to deal with these aspects: string theory reduced on the internal space of the holographic background realizes the symTFT, and BPS branes describe the charged and topological operators of the dual theory. However, the characterization of continuous symmetry operators in holography is still unclear.
In this talk, I will briefly review how topological operators implementing continuous symmetries captured by fluctuations of the RR or NSNS gauge fields are realized in terms of non-BPS branes. Then I will extend this concept to R-symmetries, realized as isometries of the internal space of the holographic background, which will be implemented by another non-BPS object, namely a non-BPS KK monopole. I will then apply this general result to the 4d Klebanov-Witten theory. I will review its symmetry Theory (symTh), obtained by reducing supergravity on the dual background, and I will describe how its charged and topological operators and their anomalies are realized by BPS and non-BPS branes respectively, providing a non-trivial check of the proposal.
Based on JHEP 02 (2025), 066 with O. Bergman, E. Garcia-Valdecasas, and D. Rodriguez-Gomez, and on JHEP 10 (2025), 107 with H. Calvo and D. Rodriguez-Gomez.
