In this paper, we prove that every pointwise semi-slant warped product submanifold M = NT xf N? in a nearly Kenmotsu manifold ?M satisfies the following inequality: ||h||2 ? 2n2 (1 + 10/9 cot2?)(|| ??(lnf)||2-1), where n2 dimN?, ??(ln f) is gradient of ln f and ||h|| length second fundamental form M. The equality special cases inequality are investigated.

commutative properties of four-dimensional generalized symmetric pseudo-riemannian manifolds were considered. specially, in this paper, we studied skew-tsankov and jacobi-tsankov conditions in 4-dimensional pseudo-riemannian generalized symmetric manifolds.

We generalize the symmetry superalgebras of isometries and geometric Killing spinors on a manifold to include all hidden symmetries generated by in dimensions. show that bilinears produce special Killing–Yano forms conformal forms. After defining Lie algebra structure spinors, we construct operators as generalizations derivative spinor fields. All these constructions together constitute general...

M. Kruskal showed that each nearly-periodic dynamical system admits a formal $U(1)$ symmetry, generated by the so-called roto-rate. We prove such systems also admit nearly-invariant manifolds of order, near which rapid oscillations are suppressed. study nonlinear normal stability these slow for Hamiltonian on barely symplectic -- equipped with closed, non-degenerate $2$-forms may be degenerate ...