Results 41 to 50 of about 1,746,741 (337)
On generalized semisymmetric Riemannian manifolds
Atti della Accademia Peloritana dei Pericolanti : Classe di Scienze Fisiche, Matematiche e Naturali, 2013 There are several generalizations of the concept of semi-symmetric Riemannian manifolds. In the present paper, we consider some special types of generalized semi-symmetric Riemannian manifolds with positive or negative defined curvature operator or ...
Josef Mikes, Sergey E. Stepanov
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Sectional curvatures of K�hler moduli
Mathematische Annalen, 2004 We investigate a new property for compact Kahler manifolds. Let X be a Kahler manifold of dimension n and let H^{1,1} denote the (1,1) part of its real second cohomology. On this space, we have an degree n form given by cup product. Let K denote the open cone of Kahler classes in H^{1,1}, and K_1 the level set consisting of classes in K on which the n ...
P. M. H. Wilson, P. M. H. Wilson
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On the Tachibana numbers of closed manifolds with pinched negative sectional curvature
Дифференциальная геометрия многообразий фигур, 2020 Conformal Killing form is a natural generalization of conformal Killing vector field. These forms were extensively studied by many geometricians. These considerations were motivated by existence of various applications for these forms.
S.E. Stepanov, I. I. Tsyganok
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Qualar curvatures of pseudo Riemannian manifolds and pseudo Riemannian submanifolds
AIMS Mathematics, 2021 Some relations involving the qualar and null sectional curvatures for a pseudo Riemannian manifold are obtained. These curvatures are also investigated for pseudo-Riemannian submanifolds.
Mehmet Gülbahar
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Characterization of Holomorphic Bisectional Curvature of GCR-Lightlike Submanifolds
Advances in Mathematical Physics, 2012 We obtain the expressions for sectional curvature, holomorphic sectional curvature, and holomorphic bisectional curvature of a GCR-lightlike submanifold of an indefinite Kaehler manifold.
Sangeet Kumar +2 more
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Four-dimensional cohomogeneity one Ricci flow and nonnegative sectional curvature [PDF]
Communications in analysis and geometry, 2016 We exhibit the first examples of closed 4-manifolds with nonnegative sectional curvature that lose this property when evolved via Ricci flow.
R. G. Bettiol, Anusha M. Krishnan
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Nonconnected moduli spaces of nonnegative sectional curvature metrics on simply connected manifolds [PDF]
, 2016 We show that in each dimension 4n+3 , n⩾1 , there exist infinite sequences of closed smooth simply connected manifolds M of pairwise distinct homotopy type for which the moduli space of Riemannian metrics with nonnegative sectional curvature has ...
Anand Dessai, S. Klaus, W. Tuschmann
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On Sectional Curvatures of (ε)-Sasakian Manifolds
International Journal of Mathematics and Mathematical Sciences, 2007 We obtain some basic results for Riemannian curvature tensor of (ε)-Sasakian manifolds and then establish equivalent relations among φ-sectional curvature, totally real sectional curvature, and totally real bisectional curvature for (ε)-Sasakian ...
Rakesh Kumar +2 more
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An estimate of sectional curvatures of hypersurfaces with positive Ricci curvatures [PDF]
Proceedings of the Edinburgh Mathematical Society, 1995 Let M be a hypersurface in Euclidean space and let the Ricci curvature of M be bounded below by some nonnegative constant. In this paper, we estimate the sectional curvature of M in terms of the lower bound of Ricci curvature and the upper bound of mean curvature.
Ju Seon Kim, Sang Og Kim
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On projectivized vector bundles and positive holomorphic sectional curvature [PDF]
, 2016 We generalize a construction of Hitchin to prove that, given any compact K\"ahler manifold $M$ with positive holomorphic sectional curvature and any holomorphic vector bundle $E$ over $M$, the projectivized vector bundle ${\mathbb P}(E)$ admits a K ...
A. Alvarez, Gordon Heier, F. Zheng
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