Ⅰ. DEFINITIONS AND SOME KNOWN RESULTSDefinition 1.1. Let (M, g) be a pseudo-Riemannian manifold and I be a paracomplex structure on M (the definition of paracomplex structure can be found in [1] and [2]). If the
基金Project supported by the National Natural Science Foundation of China.
文摘Ⅰ. DEFINITIONS AND SOME KNOWN RESULTSDefinition 1.1. Let (M, g) be a pseudo-Riemannian manifold and I be a paracomplex structure on M (the definition of paracomplex structure can be found in [1] and [2]). If the
