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We present in this paper a \boundary version" for theorems about minimality of volume and energy functionals on a spherical domain of threedimensional Euclidean sphere.

Differential Geometry · Mathematics 2011-01-28 Fabiano G. B. Brito , André Gomes , Giovanni S. Nunes

We present a boundary version of a theorem about solenoidal unit vector fields with minimum energy on a spherical domain of an odd dimensional Euclidean sphere.

Differential Geometry · Mathematics 2013-07-26 Fabiano Brito , André Gomes

We give a new proof of the well-known result that the minimal volume vector fields on $\mathbb{S}^3(r)$ are the Hopf vector fields. Such proof relies again on calibration theory, arising here from a systematic point of view given by a…

Differential Geometry · Mathematics 2025-10-17 Rui Albuquerque

We provide a lower value for the volume of a unit vector field tangent to an antipodally Euclidean sphere $\mathbb{S}^2$ depending on the length of an ellipse determined by the indexes of its singularities. In addition, for minimizing…

Differential Geometry · Mathematics 2020-11-11 Fabiano Brito , Jackeline Conrado , Adriana Nicoli , Ícaro Gonçalves

We provide a lower value for the volume of a unit vector field tangent to an antipodally Euclidean sphere $\mathbb{S}^2$ depending on the length of an ellipse determined by the indexes of its singularities.

Differential Geometry · Mathematics 2021-02-23 Fabiano G. B. Brito , Jackeline Conrado , Icaro Gonçalves , Adriana V. Nicoli

We consider the problem of minimal volume vector fields on a given Riemann surface, specialising on the case of $M^\star$, that is, the arbitrary radius 2-sphere with two antipodal points removed. We discuss the homology theory of the unit…

Differential Geometry · Mathematics 2023-07-20 Rui Albuquerque

We establish in this paper a sharp lower bound for the area of a unit vector field $V$ defined on some spherical annuli in the Euclidean sphere $\mathbb{S}^2$.

Differential Geometry · Mathematics 2025-02-11 Fabiano Brito , Jackeline Conrado , João Lucas , Giovanni Nunes

The stability of the 3-dimensional Hopf vector field, as a harmonic section of the unit tangent bundle, is viewed from a number of different angles. The spectrum of the vertical Jacobi operator is computed, and compared with that of the…

Differential Geometry · Mathematics 2009-10-31 A. Higuchi , B. S. Kay , C. M. Wood

This note provides an affirmative answer to a question of Viterbo concerning the existence of nondiffeomorphic contact forms that share the same Reeb vector field. Starting from an observation by Croke-Kleiner and Abbondandolo that such…

Symplectic Geometry · Mathematics 2024-01-17 Hansjörg Geiges

We use the theory of calibrations to write the equation of a minimal volume vector field on a given Riemann surface.

Differential Geometry · Mathematics 2023-04-18 Rui Albuquerque

The Poincare-Hopf theorem tells us that given a smooth, structurally stable vector field on a surface of genus g, the number of saddles is 2-2g less than the number of sinks and sources. We generalize this result by introducing a more…

Differential Geometry · Mathematics 2015-03-19 John Berman , Sergei Bernstein

Using a quantum field theoretic description of the photon it is shown that, as intuitively expected but not before theoretically proven, the vector potential of a photon has a likely amplitude associated with a discrete frequency and…

Quantum Physics · Physics 2023-01-30 Anthony Rizzi

Given a flow on a 3-dimensional integral homology sphere, we give a formula for the Euler characteristic of its transverse surfaces, in terms of boundary data only. We illustrate the formula with several examples, in particular with…

Dynamical Systems · Mathematics 2020-09-28 Pierre Dehornoy , Ana Rechtman

We prove that the Hopf vector field is a unique one among geodesic covariantly normal unit vector fields on spheres such that the submanifold generated by the field is totally geodesic in the unit tangent bundle with Sasaki metric. As…

Differential Geometry · Mathematics 2007-05-23 A. Yampolsky

In these short notes we characterize the loxodromic unit vector fields on antipodally punctured Euclidean spheres as the only ones achieving a lower bound for the volume functional depending on the Poincar\'e indexes around their…

Differential Geometry · Mathematics 2019-10-01 Jackeline Conrado , Adriana V. Nicoli , Giovanni N. Nunes

We prove that all star vector fields, including Lorenz attractors and multisingular hyperbolic vector fields, admit the intermediate entropy property. To be precise, if $X$ is a star vector field with $h_{top}(X)>0$, then for any $h\in…

Dynamical Systems · Mathematics 2018-08-28 Ming Li , Yi Shi , Shirou Wang , Xiaodong Wang

In this paper, we characterize arbitrary polynomial vector fields on $S^n$. We establish a necessary and sufficient condition for a degree one vector field on the odd-dimensional sphere $S^{2n-1}$ to be Hamiltonian. Additionally, we…

Dynamical Systems · Mathematics 2024-12-04 Supriyo Jana , Soumen Sarkar

We study the projections in vector spaces over finite fields. We prove finite fields analogues of the bounds on the dimensions of the exceptional sets for Euclidean projection mapping. We provide examples which do not have exceptional…

Classical Analysis and ODEs · Mathematics 2017-07-31 Changhao Chen

We construct the space of vector fields on quantum groups . Its elements are products of the known left invariant vector fields with the elements of the quantum group itself. We also study the duality between vector fields and 1-forms. The…

High Energy Physics - Theory · Physics 2007-05-23 P. Aschieri

We present a computational method for reconstructing a vector field on a convex polytope $\mathcal{P} \subset \mathbb{R}^d$ of arbitrary dimension from discrete samples. We specifically address the scenario where the vector field is subject…

Dynamical Systems · Mathematics 2026-02-03 Junyan Chu , Shizuo Kaji
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