Results 31 to 40 of about 130 (124)

Oriented 6‐dimensional submanifolds in the octonians, III

International Journal of Mathematics and Mathematical Sciences, Volume 18, Issue 1, Page 111-120, 1995., 1993
In this paper, we classify 6‐dimensional almost Hermitian submanifolds in the octonians 𝕆 according to the classification introduced by A. Gray and L. Hervella. We give new examples of quasi‐Käthler and ∗‐Einstein submanifolds in 𝕆. Also, we prove that a 6‐dimensional weakly ∗‐Einstein Hermitian submanifold in 𝕆 is totally geodesic.
Hideya Hashimoto
wiley   +1 more source

Geodesics and magnetic curves in the 4-dim almost Kähler model space F4

Complex Manifolds
We study geodesics and magnetic trajectories in the model space F4{{\rm{F}}}^{4}. The space F4{{\rm{F}}}^{4} is isometric to the 4-dim simply connected Riemannian 3-symmetric space due to Kowalski. We describe the solvable Lie group model of F4{{\rm{F}}}^
Erjavec Zlatko, Inoguchi Jun-ichi
doaj   +1 more source

The Structure of Some Classes of 3-Dimensional Normal Almost Contact Metric Manifolds [PDF]

, 2013
. The object of the present paper is to study ξ -projectively flat and φ -projectively flat 3-dimensional normal almost contact metric manifolds. An illustrative example is given.
Uday Chand De, Abul Kalam Mondal
core  

A new class of non-Kähler metrics

Complex Manifolds
We study the stability at blow-ups and deformations of a class of Hermitian metrics whose fundamental two-form ω\omega satisfies the condition ∂∂¯ωk=0\partial \bar{\partial }{\omega }^{k}=0, for any kk between 1 and n−1n-1 (where nn is the complex ...
Ciulică Cristian
doaj   +1 more source

Complete lift of a structure satisfying FK − (−)K+1F = 0

International Journal of Mathematics and Mathematical Sciences, Volume 15, Issue 4, Page 803-808, 1992., 1992
The idea of f‐structure manifold on a differentiable manifold was initiated and developed by Yano [1], Ishihara and Yano [2], Goldberg [3] and among others. The horizontal and complete lifts from a differentiable manifold Mn of class C∞ to its cotangent bundles have been studied by Yano and Patterson [4,5].
Lovejoy S. Das
wiley   +1 more source

Locally conformal symplectic manifolds

International Journal of Mathematics and Mathematical Sciences, Volume 8, Issue 3, Page 521-536, 1985., 1985
A locally conformal symplectic (l. c. s.) manifold is a pair (M2n, Ω) where M2n(n > 1) is a connected differentiable manifold, and Ω a nondegenerate 2‐form on M such that (Uα‐ open subsets). , σα : Uα → ℝ, dΩα = 0. Equivalently, dΩ = ω∧Ω for some closed 1‐form ω. L. c. s.
Izu Vaisman
wiley   +1 more source

On a Class Almost Contact Manifolds with Norden Metric

, 2020
Certain curvature properties and scalar invariants of the manifolds belonging to one of the main classes almost contact manifolds with Norden metric are considered. An example illustrating the obtained results is given and studied.
Marta Teofilova
core  

A characterization of Gromov hyperbolicity of surfaces with variable negative curvature [PDF]

, 2009
18 pages, 4 figures.-- MSC2000 codes: 53C15, 53C21, 53C22, 53C23.MR#: MR2474116 (2009k:53091)Zbl#: Zbl 1153.53320In this paper we show that, in order to check Gromov hyperbolicity of any surface with curvature $K \leq -k^2 < 0$, we just need to verify ...
Tourís, Eva, Portilla, Ana
core   +1 more source

On a k-th Gauduchon almost Hermitian manifold

Complex Manifolds, 2022
We characterize the k-th Gauduchon condition and by applying its characterization, we reprove that a compact k-th Gauduchon, semi-Kähler manifold becomes quasi-Kähler, which tells us that in particular, a compact almost pluriclosed, semi-Kähler manifold ...
Kawamura Masaya
doaj   +1 more source

Prolongations of F‐structure to the tangent bundle of order 2

, 1991
International Journal of Mathematics and Mathematical Sciences, Volume 16, Issue 1, Page 201-204, 1993.
Lovejoy S. Das
wiley   +1 more source