Results 41 to 50 of about 20,711 (219)
On canonical 2F-planar mappings of the first type of pseudo-Riemannian spaces with f-structure
Pracì Mìžnarodnogo Geometričnogo CentruThe article is devoted to the basic questions of the theory of 2F-planar mappings of manifolds, which are endowed with a certain type affinor structure.
Irina Kurbatova, Nadiia Konovenko
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Duality on Geodesics of Cartan Distributions and Sub-Riemannian Pseudo-Product Structures
Demonstratio Mathematica, 2015 Given a five dimensional space endowed with a Cartan distribution, the abnormal geodesics form another five dimensional space with a cone structure. Then it is shown in (15), that, if the cone structure is regarded as a control system, then the space of ...
Ishikawa Goo +2 more
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On the Computation of Tensor Functions under Tensor‐Tensor Multiplications with Linear Maps
Numerical Linear Algebra with Applications, Volume 33, Issue 3, June 2026.ABSTRACT In this paper, we study the computation of both algebraic and non‐algebraic tensor functions under the tensor‐tensor multiplication with linear maps. In the case of algebraic tensor functions, we prove that the asymptotic exponent of both the tensor‐tensor multiplication and the tensor polynomial evaluation problem under this multiplication is
Jeong‐Hoon Ju, Susana López‐Moreno
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On the Geroch-Traschen class of metrics
, 2009 We compare two approaches to semi-Riemannian metrics of low regularity. The maximally 'reasonable' distributional setting of Geroch and Traschen is shown to be consistently contained in the more general setting of nonlinear distributional geometry in the
Steinbauer, R., Vickers, J.A.
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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 +2 more
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Fortschritte der Physik, Volume 74, Issue 6, June 2026.ABSTRACT We present a clear, step‐by‐step method for counting degrees of freedom and identifying constraints in general field theories. This approach, grounded in the works of Einstein, Hilbert, Cartan, Kuranishi, and, more recently, Seiler, is neither Lagrangian nor Hamiltonian in nature. Instead, it applies directly to the field equations. We offer a
Lavinia Heisenberg
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, 2009 General Relativity offers the possibility to model attributes of matter, like mass, momentum, angular momentum, spin, chirality etc. from pure space, endowed only with a single field that represents its Riemannian geometry.
Giulini, Domenico
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Covariance Estimation for Wide Data
WIREs Computational Statistics, Volume 18, Issue 2, June 2026.Covariance matrix estimation is fundamental to multivariate analysis, with applications spanning finance, genomics, climate science, and signal processing. This review synthesizes recent advances in high‐dimensional covariance estimation‐thresholding, linear and nonlinear shrinkage, graphical models, and random matrix theory‐under a unifying framework ...
Eran Raviv
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Metric tensors for homogeneous, isotropic, 5-dimensional pseudo Riemannian models [PDF]
, 1998 In this paper we study the metric tensor of a homogeneous, isotropic, 5-dimensional pseudo Riemannian space, solving the corresponding Einstein equations when the spatial component is flat, spherical or pseudo ...
Birman, Graciela Silvia +2 more
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Autoparallels and the Inverse Problem of the Calculus of Variations
Fortschritte der Physik, Volume 74, Issue 5, May 2026.ABSTRACT We prove that autoparallel curves associated with a torsion‐free but not necessarily metric‐compatible affine connection can be derived from an action principle. We explicitly construct the action functional and show by standard variational techniques that it produces the desired equations.
Lavinia Heisenberg
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