Continuous symmetry defects and brane/anti-brane systems

Abstract: We explicitly compute correlation functions with the insertion of a continuous symmetry defect in bosonic field theories. To recover the expected action, the definition of the defect must be modified to include a specific contact term. This can be regarded as a singular background gauge field for the global symmetry. It can be traced to the definition of the generating functional for current correlators, where the source is akin to a background gauge field for the symmetry. For holographic theories, it has been proposed that continuous symmetry defects are realized in terms of non-BPS $D(q-1)$ branes. We argue that these can be regarded as $Dq/\overline{Dq}$ system and show its application to the case of the baryonic symmetry in the Klebanov-Witten theory. The $Dq/\overline{Dq}$ can be regarded as a particular regularization of the defect, holographically realizing the field theory discussion.