Results 21 to 30 of about 436 (165)

Computing Bi-Invariant Pseudo-Metrics on Lie Groups for Consistent Statistics

Entropy, 2015
In computational anatomy, organ’s shapes are often modeled as deformations of a reference shape, i.e., as elements of a Lie group. To analyze the variability of the human anatomy in this framework, we need to perform statistics on Lie groups. A Lie group
Nina Miolane, Xavier Pennec
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Weyl-ambient geometries

Nuclear Physics B, 2023
Weyl geometry is a natural extension of conformal geometry with Weyl covariance mediated by a Weyl connection. We generalize the Fefferman-Graham (FG) ambient construction for conformal manifolds to a corresponding construction for Weyl manifolds.
Weizhen Jia, Manthos Karydas, Robert G. Leigh   +2 more
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Improvement and Assessment of a Blind Image Deblurring Algorithm Based on Independent Component Analysis

Computation, 2021
The aim of the present paper is to improve an existing blind image deblurring algorithm, based on an independent component learning paradigm, by manifold calculus.
Simone Fiori
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The Dirac–Witten operator on pseudo-Riemannian manifolds [PDF]

Mathematische Zeitschrift, 2011
The authors investigate the Dirac-Witten operator for space-like spin submanifolds of pseudo-Riemannian manifolds, and when the normal spin bundles are odd-dimensional they derive new lower bounds for the eigenvalues. As an application, they prove the generalized positive mass theorem of general relativity.
Chen, Daguang, Hijazi, Oussama, Zhang, Xiao   +2 more
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Szabo Osserman IP pseudo-Riemannian manifolds

Publicationes Mathematicae Debrecen, 2003
We construct a family of pseudo-Riemannian manifolds so that the skew-symmetric curvature operator, the Jacobi operator, and the Szabo operator have constant eigenvalues on their domains of definition. This provides new and non-trivial examples of Osserman, Szabo, and IP manifolds. We also study when the associated Jordan normal form of these operators
Gilkey, Peter B., Ivanova, Raina, Zhang, Tan   +2 more
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Four-Dimensional Semi-Riemannian Szabó Manifolds

Journal of Mathematics, 2020
In this paper, we prove that the deformed Riemannian extension of any affine Szabó manifold is a Szabó pseudo-Riemannian metric and vice versa. We prove that the Ricci tensor of an affine surface is skew-symmetric and nonzero everywhere if and only if ...
Abdoul Salam Diallo, Punam Gupta
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OSSERMAN LIGHTLIKE HYPERSURFACE CASES

Al-Ulum
In this study, we constructed four examples of light-like hypersurfaces that satisfy the conditions of an Osserman manifold, based on the characterisation of light-like hypersurfaces of a pseudo-Riemannian manifold of dimension m+2.
Paulin Shakwanda Mulebu, Oscar Lungiambudila Mamona, Gerard Tawaba Musian Ta-Yen, Alain Musesa Landa, Michael Kilela Makiese   +4 more
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Complete curvature homogeneous pseudo-Riemannian manifolds [PDF]

Classical and Quantum Gravity, 2004
Update paper to fix misprints in original ...
Gilkey, P., Nikčević, S.
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Left-invariant paracontact metric structure on a group Sol

Дифференциальная геометрия многообразий фигур
Among Thurston's famous list of eight three-dimensional geometries is the geometry of the manifold Sol. The variety Sol is a connected simply connected Lie group of real matrices of a special form.
M. V. Sorokina, O. P. Surina
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A New Class of Contact Pseudo Framed Manifolds with Applications

International Journal of Mathematics and Mathematical Sciences, 2021
In this paper, we introduce a new class of contact pseudo framed (CPF)-manifolds M,g,f,λ,ξ by a real tensor field f of type 1,1, a real function λ such that f3=λ2f where ξ is its characteristic vector field. We prove in our main Theorem 2 that M admits a
K. L. Duggal
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