String lunch - Andrea Marzolla Seminar

In any QFT, explicit and spontaneous breakings of a global symmetry correspond to specific Ward identities among two-point functions, which can be derived in a very general fashion. We retrieve those identities in a minimal AdS/CFT setup, thanks to holographic renormalization. The same story holds, even if with some interesting subtleties, also in two boundary dimensions, showing the breakdown of Coleman theorem in the strict large N limit. We provide as well some explicit analytic solutions, for 3 and 2 dimensions, which exhibit the gapless Goldstone pole in the scalar correlator.