Results 71 to 80 of about 90,046 (220)

Sub-Riemannian geometry and Lie groups. Part II. Curvature of metric spaces, coadjoint orbits and associated representations

open access: yes, 2004
This paper is the third in a series dedicated to the fundamentals of sub-Riemannian geometry and its implications in Lie groups theory: "Sub-Riemannian geometry and Lie groups.
Buliga, Marius
core   +1 more source

Vector‐Based and Machine Learning Approaches for Pore Network Parameters Analysis

open access: yesGeophysical Prospecting, Volume 74, Issue 1, January 2026.
ABSTRACT Accurate characterization of pore structures in carbonate rocks is critical for evaluating fluid flow and storage capacity in subsurface reservoirs, a key concern in geophysical exploration and reservoir engineering. This study proposes a hybrid digital rock physics workflow that integrates deep learning–based segmentation, vectorial geometric
José Frank V. Gonçalves   +4 more
wiley   +1 more source

A Comprehensive Review of Golden Riemannian Manifolds

open access: yesAxioms
In differential geometry, the concept of golden structure represents a compelling area with wide-ranging applications. The exploration of golden Riemannian manifolds was initiated by C. E. Hretcanu and M.
Bang-Yen Chen   +2 more
doaj   +1 more source

Chen’s Ricci inequalities and topological obstructions on null hypersurfaces of a Lorentzian manifold

open access: yesJournal of Inequalities and Applications, 2018
Given a null hypersurface of a Lorentzian manifold, we isometrically immerse a null hypersurface equipped with the Riemannian metric (induced on it by the rigging) into a Riemannian manifold suitably constructed on the Lorentzian manifold.
Karimumuryango Ménédore
doaj   +1 more source

Positive paths in diffeomorphism groups of manifolds with a contact distribution

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract Given a cooriented contact manifold (M,ξ)$(M,\xi)$, it is possible to define a notion of positivity on the group Diff(M)$\mathrm{Diff}(M)$ of diffeomorphisms of M$M$, by looking at paths of diffeomorphisms that are positively transverse to the contact distribution ξ$\xi$.
Jakob Hedicke
wiley   +1 more source

Determining Levels of Affective States with Riemannian Geometry Applied to EEG Signals

open access: yesApplied Sciences
Emotion recognition from electroencephalography (EEG) often relies on Euclidean features that ignore the curved geometry of covariance matrices. We introduce a Riemannian-manifold pipeline which, combined with the Fisher Geodesic Minimum Distance to Mean
Agnieszka Wosiak   +2 more
doaj   +1 more source

The GJMS operators in geometry, analysis and physics

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 1, January 2026.
Abstract The GJMS operators, introduced by Graham, Jenne, Mason and Sparling, are a family of conformally invariant linear differential operators with leading term a power of the Laplacian. These operators and their method of construction have had a major impact in geometry, analysis and physics.
Jeffrey S. Case, A. Rod Gover
wiley   +1 more source

A theorem concerning Fourier transforms: A survey

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 1, January 2026.
Abstract In this note, we highlight the impact of the paper G. H. Hardy, A theorem concerning Fourier transforms, J. Lond. Math. Soc. (1) 8 (1933), 227–231 in the community of harmonic analysis in the last 90 years, reviewing, on one hand, the direct generalizations of the main results and, on the other hand, the different connections to related areas ...
Aingeru Fernández‐Bertolin, Luis Vega
wiley   +1 more source

Siegel–Veech constants for cyclic covers of generic translation surfaces

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 1, January 2026.
Abstract We compute the asymptotic number of cylinders, weighted by their area to any nonnegative power, on any cyclic branched cover of any generic translation surface in any stratum. Our formulae depend only on topological invariants of the cover and number‐theoretic properties of the degree: in particular, the ratio of the related Siegel–Veech ...
David Aulicino   +4 more
wiley   +1 more source

Some elementary observations regarding reductive Cartan geometries

open access: yes, 2016
After defining generalizations of the notions of covariant derivatives and geodesics from Riemannian geometry for reductive Cartan geometries in general, various results for reductive Cartan geometries analogous to important elementary results from ...
Erickson, Jacob W.
core  

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