On 3-dimensional generalized -contact metric manifolds.
On -dimensional Lie groups as quasi-Kähler manifolds with Killing Norden metric.
On a Bianchi-type identity for the almost hermitian manifolds
Almost hermitian manifolds, whose Riemann curvature tensor satisfies an almost complex Bianchi-type identity, are considered. Some local and global theorems are proved. The special cases of parakähler manifolds and of Kähler manifolds are examined.
On a class of exact locally conformal cosymplectic manifolds.
On a Class of Hermitian Manifolds.
On a class of tangential Cauchy-Riemann maps
On a Natural Algebraic Affine Connection on the Space of Almost Complex Structures and the Curvature of Teichmüller Space with Respect to its Weil-Petersson Metric.
On a Riemannian Manifold M with Structures Defined by Nilpotent Operators
On a structure satisfying .
On a theorem of Chekanov
A proof of the Chekanov theorem is discussed from a geometric point of view. Similar results in the context of projectivized cotangent bundles are proved. Some applications are given.
On a type of manifolds over algebra of dual numbers
On a weakly symmetric Riemannian manifold admitting a special type of semi-symmetric metric connection.
On almost cosymplectic (−1, μ, 0)-spaces
In our previous paper, almost cosymplectic (κ, μ, ν)-spaces were defined as the almost cosymplectic manifolds whose structure tensor fields satisfy a certain special curvature condition. Amongst other results, it was proved there that any almost cosymplectic (κ, μ, ν)-space can be -homothetically deformed to an almost cosymplectic −1, μ′, 0)-space. In the present paper, a complete local description of almost cosymplectic (−1, μ, 0)-speces is established: “models” of such spaces are constructed,...
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 alpha-Kenmotsu manifolds satisfying certain conditions.