Tom Pugh (Imperial)
The study of supersymmetric theories has lead to the construction of a large number of interesting models. However, the Lagrangians describing most of these models are in fact only invariant under a SUSY transformation up to a total derivative. If the manifold the theory is phrased on has a boundary this will mean that the action varies into a surface term and so is not invariant in the usual way. The consideration of supersymmetric actions on manifolds with boundaries is therefore more complicated than in the boundaryless case.
Due to the relevance of subjects such as the AdS/CFT correspondence, Randall-Sundrum scenarios and Horava-Witten constructions, it has become increasingly important to better understand the large class of supersymmetric models which involve boundaries. This has lead to the development of the "SUSY without B.C." program, which I will review. I will then describe a new approach to this subject in terms of relative cohomology in superspace, which we will refer to as `Ectoplasm with an Edge'.
Arnold Sommerfeld Center