Lightlike hypersurfaces in indefinite -manifolds
arXiv:0803.3896
Abstract
In a metric -manifold we study lightlike hypersurfaces tangent to the characteristic vector fields, and owing to the presence of the -structure, we determine some decompositions of and of a chosen screen distribution obtaining two distributions invariant with respect to the structure. We discuss the existence of a -structure on a lightlike hypersurface and, under suitable hypotheses, we obtain an indefinite -structure on the leaves of an integrable distribution. The existence of totally umbilical lightlike hypersurfaces of an indefinite -space form is also discussed. Finally, we explicitely describe a lightlike hypersurface of an indefinite -manifold.
19 pages, no figures