Riemannian almost product and para-Hermitian cotangent bundles of general natural lift type

Abstract

We characterize the almost product and locally product structures of general natural lift type on the cotangent bundle of a Riemannian manifold. We find the conditions under which the cotangent bundle endowed with the constructed almost product (locally product) structure and with a pseudo-Riemannian metric obtained as a general natural lift of the metric from the base manifold, is a Riemannian almost product (locally product) or an (almost) para-Hermitian manifold. Finally, by studying the closedness of the 2-form associated to the obtained (almost) para-Hermitian structure, we characterize the general natural (almost) para-Kahlerian structures on the cotangent bundle.