On almost cosymplectic manifolds with the structure vector field belonging to the -nullity distribution.
On Almost Generalized Weakly Symmetric Kenmotsu Manifolds
This paper aims to introduce the notions of an almost generalized weakly symmetric Kenmotsu manifolds and an almost generalized weakly Ricci-symmetric Kenmotsu manifolds. The existence of an almost generalized weakly symmetric Kenmotsu manifold is ensured by a non-trivial example.
On almost hyperHermitian structures on Riemannian manifolds and tangent bundles
Some results concerning almost hyperHermitian structures are considered, using the notions of the canonical connection and the second fundamental tensor field h of a structure on a Riemannian manifold which were introduced by the second author. With the help of any metric connection on an almost Hermitian manifold M an almost hyperHermitian structure can be constructed in the defined way on the tangent bundle TM. A similar construction was considered in [6], [7]. This structure includes two basic...
On almost Kähler type (2G₃) 4-manifolds
We study four-dimensional almost Kähler manifolds (M,g,J) which satisfy A. Gray's condition (G₃).
On almost product and almost decomposable manifolds.
On almost pseudo-conformally symmetric Ricci-recurrent manifolds with applications to relativity
The object of the present paper is to study almost pseudo-conformally symmetric Ricci-recurrent manifolds. The existence of almost pseudo-conformally symmetric Ricci-recurrent manifolds has been proved by an explicit example. Some geometric properties have been studied. Among others we prove that in such a manifold the vector field corresponding to the 1-form of recurrence is irrotational and the integral curves of the vector field are geodesic. We also study some global properties of such a...
On Almost Pseudo-Z-symmetric Manifolds
The object of the present paper is to study almost pseudo-Z-symmetric manifolds. Some geometric properties have been studied. Next we consider conformally flat almost pseudo-Z-symmetric manifolds. We obtain a sufficient condition for an almost pseudo-Z-symmetric manifold to be a quasi Einstein manifold. Also we prove that a totally umbilical hypersurface of a conformally flat () is a manifold of quasi constant curvature. Finally, we give an example to verify the result already obtained in Section...
On almost-Riemannian surfaces
An almost-Riemannian structure on a surface is a generalized Riemannian structure whose local orthonormal frames are given by Lie bracket generating pairs of vector fields that can become collinear. The distribution generated locally by orthonormal frames has maximal rank at almost every point of the surface, but in general it has rank 1 on a nonempty set which is generically a smooth curve. In this paper we provide a short introduction to 2-dimensional almost-Riemannian geometry highlighting its...
On alpha-Kenmotsu manifolds satisfying certain conditions.
On an Einstein projective Sasakian manifold.
On an extended contact Bochner curvature tensor on contact metric manifolds
On Sasakian manifolds, Matsumoto and Chūman [3] defined a contact Bochner curvature tensor (see also Yano [7]) which is invariant under D-homothetic deformations (for D-homothetic deformations, see Tanno [5]). On the other hand, Tricerri and Vanhecke [6] defined a general Bochner curvature tensor with conformal invariance on almost Hermitian manifolds. In this paper we define an extended contact Bochner curvature tensor which is invariant under D-homothetic deformations of contact metric manifolds;...
On an integral formula
On applications of the Yano–Ako operator
In this paper we consider a method by which a skew-symmetric tensor field of type (1,2) in can be extended to the tensor bundle on the pure cross-section....
On Asymmetric Distances
In this paper we discuss asymmetric length structures and asymmetric metric spaces. A length structure induces a (semi)distance function; by using the total variation formula, a (semi)distance function induces a length. In the first part we identify a topology in the set of paths that best describes when the above operations are idempotent. As a typical application, we consider the length of paths defined by a Finslerian functional in Calculus of Variations. In the second part we generalize the...
On Asymptotic Directions of Minimal Immersions.
On Asymptotic Volume of Tori.
On balls and totally geodesic submanifolds
On Berwald and Wagner manifolds.
On bilinear structures on differentiable manifolds
On Blaschke manifolds and harmonic manifolds