On the geometry of some special kenmotsu structures

The present thesis consists of six chapters. The first chapter of this thesis is devoted to the introduction part which states the aim and usage areas of the thesis. The second chapter contains some fundamental definitions and theorems which will be used in other chapters in details. From third chapter to the last chapter, each chapter of this thesis consist original results. The third chapter consists some original results about alpha Kenmotsu manifolds. In the first part of this chapter, we introduce some curvature problems with some symmetry conditions. On the other hand, in the second part of this chapter, we give some results about ksi-umbilical, totally ksi-geodesic and ksi-minimal submanifolds associated with an -vector field on a submanifold M of an alpha-Kenmotsu manifold . The fourth chapter contains some curvature problems of nearly Kenmotsu manifold. In addition to this, we study geometry of the leaves of distributions of hemi-slant submanifolds. In the fifth chapter we consider some curvature problems and some submanifolds of para-Kenmotsu manifolds. In these submanifolds, we search the integrability of distributions of submanifolds which were handled in the submanifolds part and the existence of some submanifolds. In the last part, some classifications of Lorentz Kenmotsu manifolds are given using some curvature properties under some symmetry conditions. In addition to we give some results about contact generic normal submanifolds of Lorentz Kenmotsu manifolds.