Results 21 to 30 of about 1,769 (87)
A note on Chen′s basic equality for submanifolds in a Sasakian space form
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 11, Page 711-716, 2003., 2003 It is proved that a Riemannian manifold M isometrically immersed in a Sasakian space form M˜(c) of constant φ‐sectional curvature c < 1, with the structure vector field ξ tangent to M, satisfies Chen′s basic equality if and only if it is a 3‐dimensional minimal invariant submanifold.
Mukut Mani Tripathi +2 more
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Some submersions of CR‐hypersurfaces of Kaehler‐Einstein manifold
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 18, Page 1137-1144, 2003., 2003 The Riemannian submersions of a CR‐hypersurface M of a Kaehler‐Einstein manifold M˜ are studied. If M is an extrinsic CR‐hypersurface of M˜, then it is shown that the base space of the submersion is also a Kaehler‐Einstein manifold.
Vittorio Mangione
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Geometry of conformal η-Ricci solitons and conformal η-Ricci almost solitons on paracontact geometry
Open Mathematics, 2022 We prove that if an η\eta -Einstein para-Kenmotsu manifold admits a conformal η\eta -Ricci soliton then it is Einstein. Next, we proved that a para-Kenmotsu metric as a conformal η\eta -Ricci soliton is Einstein if its potential vector field VV is ...
Li Yanlin +3 more
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Foliations by minimal surfaces and contact structures on certain closed 3‐manifolds
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 21, Page 1323-1330, 2003., 2003 Let (M, g) be a closed, connected, oriented C∞ Riemannian 3‐manifold with tangentially oriented flow F. Suppose that F admits a basic transverse volume form μ and mean curvature one‐form κ which is horizontally closed. Let {X, Y} be any pair of basic vector fields, so μ(X, Y) = 1.
Richard H. Escobales Jr.
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The local moduli of Sasakian 3‐manifolds
International Journal of Mathematics and Mathematical Sciences, Volume 32, Issue 2, Page 117-127, 2002., 2002 The Newman‐Penrose‐Perjes formalism is applied to Sasakian 3‐manifolds and the local form of the metric and contact structure is presented. The local moduli space can be parameterised by a single function of two variables and it is shown that, given any smooth function of two variables, there exists locally a Sasakian structure with scalar curvature ...
Brendan S. Guilfoyle
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Ricci curvature of submanifolds in Kenmotsu space forms
International Journal of Mathematics and Mathematical Sciences, Volume 29, Issue 12, Page 719-726, 2002., 2002 In 1999, Chen established a sharp relationship between the Ricci curvature and the squared mean curvature for a submanifold in a Riemannian space form with arbitrary codimension. Similar problems for submanifolds in complex space forms were studied by Matsumoto et al.
Kadri Arslan +4 more
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On curvature tensors of Norden and metallic pseudo-Riemannian manifolds
Complex Manifolds, 2019 We study some properties of curvature tensors of Norden and, more generally, metallic pseudo-Riemannian manifolds. We introduce the notion of J-sectional and J-bisectional curvature of a metallic pseudo-Riemannian manifold (M, J, g) and study their ...
Blaga Adara M., Nannicini Antonella
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Essential points of conformal vector fields
, 2010 For a conformal vector field $\xi$ on a Riemannian manifold, we say that a point is essential if there is no local metric in the conformal class for which $\xi$ is Killing. We show that the only essential points are isolated zeros of $\xi$.
Belgun, Florin +2 more
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Novel Theorems on Spacetime Admitting Pseudo‐W2 Curvature Tensor
Journal of Mathematics, Volume 2026, Issue 1, 2026.This paper investigates spacetime manifolds admitting a pseudo‐W2 curvature tensor. We show that a pseudo‐W2 flat spacetime is an Einstein manifold and therefore has constant curvature. Moreover, when the manifold satisfies the Einstein field equations (EFE), with a cosmological constant, the associated energy–momentum tensor is covariantly constant ...
B. B. Chaturvedi +3 more
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Chern classes of integral submanifolds of some contact manifolds
International Journal of Mathematics and Mathematical Sciences, Volume 32, Issue 8, Page 481-490, 2002., 2002 A complex subbundle of the normal bundle to an integral submanifold of the contact distribution in a Sasakian manifold is given. The geometry of this bundle is investigated and some results concerning its Chern classes are obtained.
Gheorghe Pitiş
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