Killing forms on Riemannian manifolds are differential forms whose covariant derivative is totally skew-symmetric. We prove that on a compact manifold with holonomy G(2) or Spin(7) any Killing form has to be parallel. The main tool is a universal Weitzenbock formula. We show, how such a formula can be obtained for any given holonomy group and any representation defining a vector bundle. (c) 2005 Published by Elsevier B.V.
机构:
Petr Gas Univ Ploiesti, Dept Math Modelling Econ Anal & Stat, Ploiesti 100680, Romania
Univ Bucharest, Fac Math & Comp Sci, Res Ctr Geometry Topol & Algebra, Bucharest 060042, RomaniaUniv Craiova, Dept Math, Craiova 200585, Romania