I will review the old idea of studying QFTs on AdS background to control strong coupling effects. We study dynamical mass generation in some 2d asymptotically free theories in AdS backgrounds. At weak coupling a Dirichlet boundary condition ensures that the bulk field is exactly massless.
At strong coupling a marginal boundary singlet operator appears, destabilizing the BCFT and leading to a boundary phase transition. The endpoint of this boundary flow allows for a massive bulk phase and interpolates with the flat spacetime physics. We conjecture that such a phenomenon is also responsible for confinment in 4d gauge theories on AdS background.
Based on work to appear with Lorenzo di Pietro, Shota Komatsu and Ziming Ji.