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On some generalized Einstein metric conditions on hypersurfaces in semi-Riemannian space forms

Ryszard Deszcz, Małgorzata Głogowska, Marian Hotloś, Leopold Verstraelen (2003)

Colloquium Mathematicae

Solutions of the P. J. Ryan problem as well as investigations of curvature properties of Cartan hypersurfaces and Ricci-pseudosymmetric hypersurfaces lead to curvature identities holding on every hypersurface M isometrically immersed in a semi-Riemannian space form. These identities, under some assumptions, give rises to new generalized Einstein metric conditions on M. We investigate hypersurfaces satisfying such curvature conditions.

On some properties of induced almost contact structures

Zuzanna Szancer (2015)

Annales Polonici Mathematici

Real affine hypersurfaces of the complex space ℂ n + 1 with a J-tangent transversal vector field and an induced almost contact structure (φ,ξ,η) are studied. Some properties of the induced almost contact structures are proved. In particular, we prove some properties of the induced structure when the distribution is involutive. Some constraints on a shape operator when the induced almost contact structure is either normal or ξ-invariant are also given.

On some type of curvature conditions

Mohamed Belkhelfa, Ryszard Deszcz, Małgorzata Głogowska, Marian Hotloś, Dorota Kowalczyk, Leopold Verstraelen (2002)

Banach Center Publications

In this paper we present a review of recent results on semi-Riemannian manifolds satisfying curvature conditions of pseudosymmetry type.

On some types of slant curves in contact pseudo-Hermitian 3-manifolds

Cihan Özgür, Şaban Güvenç (2012)

Annales Polonici Mathematici

We study slant curves in contact Riemannian 3-manifolds with pseudo-Hermitian proper mean curvature vector field and pseudo-Hermitian harmonic mean curvature vector field for the Tanaka-Webster connection in the tangent and normal bundles, respectively. We also study slant curves of pseudo-Hermitian AW(k)-type.

On special almost geodesic mappings of type π 1 of spaces with affine connection

Vladimir Berezovskij, Josef Mikeš (2004)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

N. S. Sinyukov [5] introduced the concept of an almost geodesic mapping of a space A n with an affine connection without torsion onto A ¯ n and found three types: π 1 , π 2 and  π 3 . The authors of [1] proved completness of that classification for n > 5 .By definition, special types of mappings π 1 are characterized by equations P i j , k h + P i j α P α k h = a i j δ k h , where P i j h ≡ Γ ¯ i j h - Γ i j h is the deformation tensor of affine connections of the spaces A n and A ¯ n .In this paper geometric objects which preserve these mappings are found and also closed classes of such spaces...

On special Berwald metrics.

Tayebi, Akbar, Peyghan, Esmaeil (2010)

SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]

On "special" fibred coordinates for general and classical connections

Włodzimierz M. Mikulski (2010)

Annales Polonici Mathematici

Using a general connection Γ on a fibred manifold p:Y → M and a torsion free classical linear connection ∇ on M, we distinguish some “special” fibred coordinate systems on Y, and then we construct a general connection ℱ ˜ ( Γ , ∇ ) on Fp:FY → FM for any vector bundle functor F: ℳ f → of finite order.

Currently displaying 681 – 700 of 1303