Toward exotic 6D supergravities
Yannick Bertrand, Stefan Hohenegger, Olaf Hohm, Henning Samtleben
Abstract
We investigate exotic supergravity theories in 6D with maximal (4,0) and (3,1) supersymmetry, which were conjectured by Hull to exist and to describe strong coupling limits of $\mathcal{N}=8$ theories in 5D. These theories involve exotic gauge fields with nonstandard Young tableaux representations, subject to (self-)duality constraints. We give novel actions in a $5+1$ split of coordinates whose field equations reproduce those of the free bosonic (4,0) and (3,1) theory, respectively, including the (self-)duality relations. Evidence is presented for a master exceptional field theory formulation with an extended section constraint that, depending on the solution, produces the (4,0), (3,1) or the conventional (2,2) theory. We comment on the possible construction of a fully nonlinear master exceptional field theory.