SO(5,5) duality in M-theory and generalized geometry
  We attempt to reformulate eleven dimensional supergravity in terms of an object that unifies the three-form and the metric and makes the M-theory duality group manifest. This short note deals with the case of where the U-duality group SO(5,5) acts in five spatial dimensions. 
David S. Berman, Hadi Godazgar and Malcolm J. Perry
hep-th