Let M be a real hypersurface with almost contact metric structure (φ, ξ, η, g) in a nonflat complex space form Mn(c). We denote S and Rξ by the Ricci tensor of M and by the structure Jacobi operator with respect to the ...

Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (φ, ξ, η, g) in a complex space form Mn+1(c), c ̸= 0. We denote by Rξ and RX′ be the structure Jacobi operator with re- spect to ...