For a local quantum field theory in anti-de Sitter space with conformal boundary conditions but without dynamical gravity, the boundary theory is generically a non-local conformal field theory. Such theories can support conformal defects, but the standard local-CFT arguments based on a boundary stress tensor and conserved currents do not apply. We argue that, under general assumptions, displacement and tilt operators nevertheless exist and have protected quantum numbers. The mechanism is a Goldstone-type phenomenon in AdS: defect-induced symmetry breaking on the boundary is spontaneous from the viewpoint of the local bulk theory, whose Ward identities enforce the corresponding protected defect operators. We illustrate the mechanism in weakly coupled defect RG flows, long-range Landau--Ginzburg models, 4D Maxwell theory, and Yang--Mills theory in AdS. 

Biography

乔稼欣，巴黎高等师范学院物理学博士，曾在洛桑联邦理工学院从事博士后研究，现任东京大学科维理宇宙物理学与数学研究所博士后。主要从事共形场论、量子场论及其在强耦合体系中的应用研究，研究内容涉及共形自举及反德西特时空中的量子场论等方向。

Inviter: De-Liang Zhong