Page 1 Next

Displaying 1 – 20 of 110

Showing per page

On a Bianchi-type identity for the almost hermitian manifolds

Giovanni Battista Rizza (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

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 theorem of Chekanov

Emmanuel Ferrand (1997)

Banach Center Publications

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 almost cosymplectic (−1, μ, 0)-spaces

Piotr Dacko, Zbigniew Olszak (2005)

Open Mathematics

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 𝒟 -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

Kanak Kanti Baishya, Partha Roy Chowdhury, Josef Mikeš, Patrik Peška (2016)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

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

Serge Bogdanovich, Alexander Ermolitski (2004)

Open Mathematics

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 pseudo-conformally symmetric Ricci-recurrent manifolds with applications to relativity

Uday Chand De, Avik De (2012)

Czechoslovak Mathematical Journal

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 ρ corresponding to the 1-form of recurrence is irrotational and the integral curves of the vector field ρ are geodesic. We also study some global properties of such a...

On Almost Pseudo-Z-symmetric Manifolds

Uday Chand De, Prajjwal Pal (2014)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

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 A ( P Z S ) n ( n > 3 ) is a manifold of quasi constant curvature. Finally, we give an example to verify the result already obtained in Section...

Currently displaying 1 – 20 of 110

Page 1 Next