Event description
Symmetries play a fundamental role in studying quantum field theories (QFTs). They provide selection rules, constrain the dynamics of QFTs, and, through anomalies, a method to test IR or UV dualities among different QFTs. For these reasons, it is important to understand how symmetries are implemented in QFT. In the first part of the talk, we will focus on the regularization of topological operators implementing 0-form continuous symmetries in scalar field theories. In particular, we will see how insertions of these operators into correlation functions introduce divergences that need to be subtracted. The subtraction has a natural interpretation in terms of background gauging the global symmetry locally on the defect. Moreover, we will see how the improved operators need additional regularization, which can be provided by thickening the defect in the extra direction. In the second part of the talk, we will discuss how holography realizes the regularization. We will briefly review how topological operators implementing continuous symmetries are dual to non-BPS branes and how non-BPS branes can be related to brane/antibrane systems, which realize holographically the thickening of the defect. Finally, we will focus on an example, namely the 4d Klebanov-Witten theory, seeing how the non-BPS D4 brane implementing the baryonic symmetry can be related to a D5/anti D5 system and how the worldvolume gauge field of the latter may be interpreted as a background for the corresponding symmetry. Based on JHEP 02 (2025), 066 with O. Bergman, E. Garcia-Valdecasas, and D. Rodriguez-Gomez and on arXiv: 2503.04892 with H. Calvo and D. Rodriguez-Gomez.