Results 21 to 30 of about 101 (97)
Geometric inequalities for spacelike hypersurfaces in the Minkowski spacetime
, 2019 We derive a linear isoperimetric inequality and some geometric inequalities for properly located compact achronal spacelike hypersurfaces via a Minkowski-type integral formula in the Minkowski spacetime. (C) 2001 Elsevier Science B.V. All rights reserved.
Bahn, H, Hong, SP
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Pseudoinversion of degenerate metrics
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 55, Page 3479-3501, 2003., 2003 Let (M, g) be a smooth manifold M endowed with a metric g. A large class of differential operators in differential geometry is intrinsically defined by means of the dual metric g∗ on the dual bundle TM∗ of 1‐forms on M. If the metric g is (semi)‐Riemannian, the metric g∗ is just the inverse of g. This paper studies the definition of the above‐mentioned
C. Atindogbe, J.-P. Ezin, Joël Tossa
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Affine transformations and parallel lightlike vector fields on compact Lorentzian 3-manifolds
, 2014 We describe the compact Lorentzian 3-manifolds admitting a parallel lightlike vector field. The classification of compact Lorentzian 3-manifolds admitting non-isometric affine diffeomor-phisms follows, together with the complete description of these ...
Charles Boubel +3 more
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Hypersurfaces in a conformally flat space with curvature collineation
International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 3, Page 595-604, 1991., 1990 We classify the shape operators of Einstein and pseudo Einstein hypersurfaces in a conformally flat space with a symmetry called curvature collineation. We solve the fundamental problem of finding all possible forms of non‐diagonalizable shape operators.
K. L. Duggal, R. Sharma
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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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Integrable system of null curve and Betchov-Da Rios equation
Demonstratio MathematicaThis study focuses on the time evolution of a null curve using a new frame and a new transformation in Minkowski 3-space. Accordingly, Landau–Lifshitz and coupled Boussinesq-like equations for the null curve are provided in terms of the new ...
Yoon Dae Won
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Null scrolls with prescribed curvatures in Lorentz-Minkowski 3-space
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020 In Lorentz-Minkowski 3-space, null scrolls are ruled surfaces with a null base curve and null rulings. Their mean, as well as their Gaussian curvature, depends only on a parameter of a base curve. In the present paper, we obtain the first-order nonlinear
Šipuš Željka Milin +2 more
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Hermitian Manifolds of Pointwise Constant Antiholomorphic Sectional Curvatures [PDF]
, 2007 2000 Mathematics Subject Classification: Primary 53B35, Secondary 53C50.In dimension greater than four, we prove that if a Hermitian non-Kaehler manifold is of pointwise constant antiholomorphic sectional curvatures, then it is of constant sectional ...
Ganchev, Georgi, Kassabov, Ognian
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Journal of Mathematics, Volume 2026, Issue 1, 2026.This paper investigates the optimization of soliton structures on tangent bundles of statistical Kenmotsu manifolds through lifting theory. By constructing lifted statistical Kenmotsu structures using semisymmetric metric and nonmetric connections, we derive explicit expressions for the curvature tensor, Ricci operator, and scalar curvature. We analyze
Mohammad Nazrul Islam Khan +3 more
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Osculating curves in 4-dimensional semi-Euclidean space with index 2
Open Mathematics, 2017 In this paper, we give the necessary and sufficient conditions for non-null curves with non-null normals in 4-dimensional Semi-Euclidian space with indeks 2 to be osculating curves.
İlarslan Kazim +2 more
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