On certain $(f,\,g,\,u,\,v,\,łambda)$-structures
On certain $(f,\,g,\,u,\,v,\,łambda)$-structures
Yano and Okumura introduced what they call an (/, g, u, v, Λ)-structure, where / is a tensor field of type (1, 1), g a Riemannian metric, u and v 1-forms and λ is function satisfying (Y}-v(X}υ(Y] for arbitrary vector fields X and F, where U and V are vector …