A Modified Probe Limit And A New Window Into Defect CFTs*

Brane intersections have long been a the bread and butter of holography. In addition to shedding light on strongly coupled defect- and boundary-CFTS, these models lie at the core of many holographic QCD and CMT models. Here I describe a modified version of the probe approximation for a broad class of non-abelian supersymmetric brane intersections in the holographic limit, where the open strings on the probe Dq branes not only decouple, they are well-described by a Yang-Mills theory in curved space. This regime is particularly useful for studying these systems' intricate vacuum structure, which I describe for several types of intersections, and their localized finite-energy soliton states (which I discuss for the special case of D3/D5 intersections). Solitons on brane intersections have important applications in holography -- they are, for instance, the holographic realization of baryons in QCD models. Studying these states in a supersymmetric context, with all of the tools of supersymmetry at our disposal, may thus lead to new insights into the physics of these objects. (Talk based on work with Andy Royston.)