Daniel Butter, Texas A&M University

"11D supergravity in N=1/8 superspace"

Abstract: No conventional off-shell superspace exists for 11D supergravity. Nevertheless, it is possible to construct an off-shell 4D N=1 superspace with additional dependence on 7 "internal" coordinates, which reproduces 11D supergravity on-shell. This breaks manifest 11D Lorentz symmetry, but allows 1/8 of the supersymmetry to be off-shell. The action consists of two pieces: a Chern Simons action and a Kähler potential-like term. I will present its linearized form, sketch its non-linear completion, and discuss how certain curious features -- in particular the role of G2 structure -- arise from its embedding into on-shell 11D superspace.