Results 11 to 20 of about 179 (133)
Noninvariant Hypersurfaces of a Nearly Trans-Sasakian Manifolds
Journal of Mathematics, 2014 The present paper focuses on the study of noninvariant hypersurfaces of a nearly trans-Sasakian manifold equipped with (f,g,u,v,λ)-structure. Initially some properties of this structure have been discussed.
Satya Prakash Yadav, Shyam Kishor
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CR-hypersurfaces of the six-dimensional sphere [PDF]
International Journal of Mathematics and Mathematical Sciences, 1994 We proved that there does not exist a proper CR-hypersurface of S6 with parallel second fundamental form. As a result of this we showed that S6 does not admit a proper CR-totally umbilical hypersurface.
M. A. Bashir
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MathematicsIn this article, we investigate Ricci solitons occurring on spacelike hypersurfaces of Einstein Lorentzian manifolds. We give the necessary and sufficient conditions for a spacelike hypersurface of a Lorentzian manifold, equipped with a closed conformal ...
Norah Alshehri, Mohammed Guediri
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AxiomsIn this paper, we examine torse-forming vector fields to characterize extrinsic spheres (that is, totally umbilical hypersurfaces with nonzero constant mean curvatures) in Riemannian and Lorentzian manifolds.
Norah Alshehri, Mohammed Guediri
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Impact of Ambient Conformal Vector Fields on Yamabe Solitons on Riemannian Hypersurfaces
MathematicsWe investigate Yamabe solitons on Riemannian hypersurfaces induced by conformal vector fields in Riemannian and Lorentzian manifolds, with an emphasis on the tangential component.
Norah Alshehri
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Spacelike Hypersurfaces in de Sitter Space
AxiomsA closed conformal vector field in de Sitter space S1n+1c¯ induces a vector field on a spacelike hypersurface M of S1n+1c¯, referred to as the induced vector field on M. This article investigates the characterization of compact spacelike hypersurfaces in
Yanlin Li +3 more
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Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon. [PDF]
Int Sch Res Notices, 2016 A new technique is used to study a family of time‐dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson‐Walker (GRW) space‐time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)‐splitting space‐time but only some ...
Duggal KL.
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On a property of W4 -manifolds
Дифференциальная геометрия многообразий фигур, 2020 The properties of almost Hermitian manifolds belonging to the Gray — Hervella class W4 are considered. The almost Hermitian manifolds of this class were studied by such outstanding geometers like Alfred Gray, Izu Vaisman, and Vadim Feodorovich Kirichenko.
M.B. Banaru
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Some New Results on Trans‐Sasakian Manifolds
Journal of Mathematics, Volume 2022, Issue 1, 2022., 2022 In this paper, we classify trans‐Sasakian manifolds which are realized as real hypersurfaces in a complex space form. We also investigate trans‐Sasakian manifolds whose Reeb vector fields are harmonic‐Killing. The above results bring some new characterizations for the property of trans‐Sasakian 3‐manifolds.
Lei Wang, Yan Zhao, Antonio Masiello
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CONFORMAL VECTOR FIELDS AND TOTALLY UMBILIC HYPERSURFACES [PDF]
Bulletin of the Korean Mathematical Society, 2002 Let \((M^n,g)\), \(n\geq 2\), be a connected semi-Riemannian hypersurface of a semi-Riemannian space form \((\overline{M}_k^{n+1}(\overline{c}),\overline{g})\) of signature \(k\). Assume that the ambient manifold carries a conformal vector field \(V\) such that the tangential part \((V|M^n)^T\) becomes a conformal vector field on the hypersurface. Then
Kim, Dong-Soo +3 more
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