Su(3)-structures on Hypersurfaces of Manifolds with G 2 -structure

We study SU(3)-structures induced on orientable hypersurfaces of sevendimensional manifolds with G2-structure. Taking Gray-Hervella types for both structures into account, we relate the type of SU(3)-structure and the type of G2-structure with the shape tensor of the hypersurface. Additionally, we show how to compute the intrinsic SU(3)-torsion and the intrinsic G2-torsion by means of exterior algebra. Mathematics Subject Classification (2000): Primary 53C15; Secondary 53C10.