We review recently introduced geometric tools used to characterize
supersymmetric flux backgrounds, with special emphasis on Generalised
Complex Geometry as developed by Hitchin. We then proceed to describe
Exceptional Generalised Geometry, an extension of the latter formalism based
on the exceptional Lie group $E_7(7)$ which achieves a full
geometrization of all fluxes, including Ramond-Ramond fluxes. First we
present the formal structure of the theory: the Exceptional Generalized
Tangent bundle endowed with a non-trivial twisted topology and a
corresponding gerbe structure, an Exceptional Courant bracket and an
Exceptional Generalized Metric in which the bosonic degrees of freedom
of 11D supergravity (the traditional metric and the fluxes) enter on
equal footing. We then show how this formalism may be used to rewrite
part of 11D SUGRA in the language of N=1 D=4 supersymmetry and express
the corresponding effective superpotential in a manifestly $E_7(7)$
form. |