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We study the dynamics of a timelike vector field which violates Lorentz invariance when the background spacetime is in an accelerating phase in the early universe. It is shown that a timelike vector field is difficult to realize an…

High Energy Physics - Theory · Physics 2015-05-13 Seoktae Koh , Bin Hu

The Filippov convention is widely used in the literature to define vector fields on a discontinuity set of piecewise-continuous vector fields. The aim of this paper is to give a sufficient and necessary condition for an interpolation scheme…

Dynamical Systems · Mathematics 2021-09-03 Tomoharu Suda

We study the structure of $C^1$-interiors of sets of smooth vector fields with various properties of shadowing of pseudotrajectories. It is shown for which classes of reparametrizations of shadowing trajectories the corresponding interiors…

Dynamical Systems · Mathematics 2010-10-18 Sergei Yu. Pilyugin , Sergey Tikhomirov

Torse-forming vector fields are generalizations of some important vector fields. In this paper, we present some techniques to transform a proper torse-forming vector field into its special cases. Concrete examples are given.

Differential Geometry · Mathematics 2026-02-03 Beldjilali Gherici , Bayour Benaoumeur , Bouzir Habib

In this note, we provide a important considerations of a familiar topic: the gradient of a vector field. The gradient of a vector field is a common quantity represented in continuum mechanics. However, even for Cartesian coordinate systems,…

Mathematical Physics · Physics 2022-08-17 Brian D. Wood , Peeter Joot , Stephen Whitaker

This paper is concerned with the analysis of a typical singularity of piecewise smooth vector fields on $R^3$ composed by two zones. In our object of study, the cusp-fold singularity, we consider the simultaneous occurrence of a cusp…

Dynamical Systems · Mathematics 2013-06-07 Tiago De Carvalho , Marco A. Teixeira , Durval J. Tonon

Speckle patterns produced by random optical fields with two (or more) widely different correlation lengths exhibit speckle spots that are themselves highly speckled. Using computer simulations and analytic theory we present results for the…

Optics · Physics 2009-11-13 Isaac Freund , David A. Kessler

The concept of a visible point of a convex set relative to a given point is introduced. A number of basic properties of such visible point sets is developed. In particular, it is shown that this concept is useful in the study of best…

Functional Analysis · Mathematics 2012-11-07 Frank Deutsch , Hein Hundal , Ludmil Zikatanov

We define the concepts of topological particles and topological radiation. These are nothing more than connected components of defects of a vector field. To each topological particle we assign an index which is an integer which is conserved…

High Energy Physics - Theory · Physics 2008-02-03 Daniel H. Gottlieb , Geetha Samaranayake

We prove a sufficient condition for the existence of explicit first integrals for vector fields which admit an integrating factor. This theorem recovers and extends previous results in the literature on the integrability of vector fields…

Dynamical Systems · Mathematics 2012-06-15 Jaume Llibre , Daniel Peralta-Salas

Instead of evaluating the gradient field of the brightness map of an image, we propose the use of dipole vectors. This approach is obtained by adapting to the image gray-tone distribution the definition of the dipole moment of charge…

Computer Vision and Pattern Recognition · Computer Science 2009-02-27 Amelia Sparavigna

The aim of this paper is twofold. Firstly, we give easy-to-handle criteria to determine whether a given family of subsets of a vector space is a neighbourhood basis of the origin for a complete vector topology. Then, we apply these criteria…

Functional Analysis · Mathematics 2025-02-20 José L. Ansorena , Alejandro Marcos

In this paper, we give a full description of all possible singular points that occur in generic 2-parameter families of vector fields on compact 2-manifolds. This is a part of a large project aimed to a complete study of global bifurcations…

Dynamical Systems · Mathematics 2025-03-19 Dmitry A. Filimonov , Yulij S. Ilyashenko

This article studies the harmonicity of vector fields on Riemannian manifolds, viewed as maps into the tangent bundle equipped with a family of Riemannian metrics. Geometric and topological rigidity conditions are obtained, especially for…

Differential Geometry · Mathematics 2008-09-17 M. Benyounes , E. Loubeau , L. Todjihounde

We analyze a technique of obtaining turbulence power spectrum using spectral line data along the velocity coordinate, which we refer to as Velocity Coordinate Spectrum (VCS). We formalize geometrical aspects of observation through a single…

Astrophysics · Physics 2007-05-23 A. Chepurnov , A. Lazarian

A line field on a manifold is a smooth map which assigns a tangent line to all but a finite number of points of the manifold. As such, it can be seen as a generalization of vector fields. They model a number of geometric and physical…

Geometric Topology · Mathematics 2017-12-29 Thomas Lewiner , Tiago Novello , Joao Paixao , Carlos Tomei

Braided vector fields on spatial subdomains homeomorphic to the cylinder play a crucial role in applications such as solar and plasma physics, relativistic astrophysics, fluid and vortex dynamics, elasticity, and bio-elasticity. Often the…

General Topology · Mathematics 2019-09-18 Christopher B Prior , Anthony R Yeates

The purpose of this paper is to put into a noncommutative context basic notions related to vector fields from classical differential geometry. The manner of exposition is an attempt to make the material as accessible as possible to…

Quantum Algebra · Mathematics 2007-05-23 E. J. Beggs

We present an explicit formula for the mean curvature of a unit vector field on a Riemannian manifold, using a special but natural frame. As applications, we treat some known and new examples of minimal unit vector fields. We also give an…

Differential Geometry · Mathematics 2007-05-23 Alexander Yampolsky

Hypergraphs require higher-dimensional representations, which makes it more difficult to compute and interpret their spectral properties. This survey article uses the framework of hypermatrices to give an in-depth overview of the spectral…

History and Overview · Mathematics 2025-07-21 Shashwath S Shetty , K Arathi Bhat