Mustafa Gök

In this paper, we construct golden structures on locally product manifoldswith respect to a particular system of coordinate neighborhoods, namely aseparating coordinate system. We also give some results on such type ofmanifolds endowed with golden structures.

In this study, we discuss metallic structures on product manifolds and derive the Chen-Ricci inequalities for remarkable submanifolds determined by the behaviour of their tangent bundles with regard to the action of the metallic structure in a locally decomposable metallic Riemannian manifold whose components are spaces of constant curvature. Moreover, the equality cases are considered in order to characterize these submanifolds.

In this paper, we study a special class of submanifolds of almost polyNorden manifolds in the Riemannian setting. We examine the sufficient conditions for such kind of submanifolds to be totally geodesic or minimal.

This paper aims to discuss the de Rham cohomology of hemi-slant submanifolds in locally product Riemannian manifolds. The integrability and geodesical invariance conditions of the distributions derived from the definition of a hemi-slant submanifold are given. The existence and non-triviality of de Rham cohomology classes of hemi-slant submanifolds are investigated. Finally, an example is presented.

The goal of this paper is to examine invariant submanifolds in metallic Riemannian manifolds with the help of induced structures on them by the metallic Riemannian structure of the ambient manifold. We obtain a useful characterization of invariant submanifolds. We also discuss some necessary conditions for invariant submanifolds to be totally geodesic. Finally, we provide an example.

In this study, we discuss the stability of some anti-invariant submanifolds of golden Riemannian manifolds under certain conditions in terms of the Ricci curvature tensors of the ambient manifold and the submanifold.

In this study, we answer the question under what conditions a hemi-slant submanifold of locally decomposable metallic Riemannian manifolds admits a well defined canonical de Rham cohomology class. Firstly, we give the integrability and minimality conditions of the distributions arose from its definition. Later, we find some necessary conditions depending on the above-named concepts of the associated distributions for such a type of submanifold to define a de Rham cohomology class. Furthermore, we analyzed the non-triviality of this cohomology class In the end, we construct two examples which enable better expressing the main results.

In this paper, we obtain some classification theorems for totally umbilical semi-invariant submanifolds in locally decomposable metallic Riemannian manifolds. We also prove that there exist no totally umbilical proper semi-invariant submanifolds in a posivitely or negatively curved locally decomposable metallic Riemannian manifold