On the explicit expressions of the canonical 8-form on Riemannian manifolds with Spin (9) holonomy

6 pags. 1991 Mathematics Subject Classification. Primary 53C29, Secondary 53C27.Two explicit expressions of the canonical 8-form on a Riemannian manifold with holonomy group Spin(9) have been given: One by the present authors and another by Parton and Piccinni. The relation between these two expressions is obtained. Moreover, it is shown that they are different only from a combinatorial viewpoint.The first author has been supported by DGI (Spain) Project MTM2013-46961-P..Peer reviewe

Geodesic flows on Riemannian g.o. spaces

We prove the integrability of geodesic flows on the Riemannian g.o. spaces of compact Lie groups, as well as on a related class of Riemannian homogeneous spaces having an additional principal bundle structure.Comment: 12 pages, minor corrections, final versio