中文
相关论文

相关论文: A problem of Ulam about magnetic fields generated …

200 篇论文

In 1999, Khovanov showed that a link invariant known as the Jones polynomial is the Euler characteristic of a homology theory. The knot categorification problem is to find a general construction of knot homology groups, and to explain their…

几何拓扑 · 数学 2022-08-01 Mina Aganagic

An initially knotted light field will stay knotted if it satisfies a set of nonlinear, geometric constraints, i.e. the null conditions, for all space-time. However, the question of when an initially null light field stays null has remained…

数学物理 · 物理学 2017-12-11 Hridesh Kedia , Daniel Peralta-Salas , William TM Irvine

It has been argued based on electric-magnetic duality that the Jones polynomial of a knot in three dimensions can be computed by counting the solutions of certain gauge theory equations in four-dimension. And the Euler characteristic of…

高能物理 - 理论 · 物理学 2019-05-01 Jing Zhou , Jialun Ping

Using a model of idealized, crossed one-dimensional quantum wires we construct a novel model for a single electron on tunneling-coupled systems of one-dimensional quantum rings. We explore and find that topology can affect the energetics of…

介观与纳米尺度物理 · 物理学 2020-07-07 Colin Riggert , Kieran Mullen

The aims of this letter are three-fold: First is to show that nonlinear generalizations of electrodynamics support various types of knotted solutions in vacuum. The solutions are universal in the sense that they do not depend on the…

广义相对论与量子宇宙学 · 物理学 2016-08-24 E. Goulart

We show that the realisation of synthetic magnetic fields via light-matter coupling in the Lambda-scheme implements a natural geometrical construction of magnetic fields, namely as the pullback of the area element of the sphere to Euclidean…

We construct a family of exact solutions to Maxwell's equations in which the points of zero intensity form knotted lines topologically equivalent to a given but arbitrary algebraic link. These lines of zero intensity, more commonly referred…

Knot physics is the theory of the universe that not only unified all the fundamental interactions but also explores the underlying physics of quantum mechanics. In knot physics, the most important physical result is the unification of…

综合物理 · 物理学 2019-09-05 Su-Peng Kou

Problems and perspectives concerning the existence of large-scale magnetic fields are described. Heeding observations, possible origins and implications of magnetic fields in spiral galaxies and in regular clusters are scrutinized in…

高能物理 - 唯象学 · 物理学 2007-05-23 M. Giovannini

We employ the density functional Kohn-Sham method in the local spin-density approximation to study the electronic structure and magnetism of quasi one-dimensional periodic arrays of few-electron quantum dots. At small values of the lattice…

介观与纳米尺度物理 · 物理学 2015-06-25 K. Karkkainen , M. Koskinen , S. M. Reimann , M. Manninen

In the study of ribbon knots, Lamm introduced symmetric unions inspired by earlier work of Kinoshita and Terasaka. We show an identity between the twisted Alexander polynomials of a symmetric union and its partial knot. As a corollary, we…

几何拓扑 · 数学 2025-12-02 Michel Boileau , Teruaki Kitano , Yuta Nozaki

Since magnetic fields in galaxies, galactic clusters and even void regions are observed, theoretical attempts to explain their origin are strongly motivated. It is interesting to consider that inflation is responsible for the origin of the…

宇宙学与河外天体物理 · 物理学 2014-02-07 Tomohiro Fujita

We explore spin dependent transport through a magnetic quantum wire which is attached to two non-magnetic metallic electrodes. We adopt a simple tight-binding Hamiltonian to describe the model where the quantum wire is attached to two…

介观与纳米尺度物理 · 物理学 2015-03-13 Moumita Dey , Santanu K. Maiti , S. N. Karmakar

The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and…

综合物理 · 物理学 2010-11-09 P. Hraskó

We work with a generalization of knot theory, in which one diagram is reachable from another via a finite sequence of moves if a fixed condition, regarding the existence of certain morphisms in an associated category, is satisfied for every…

几何拓扑 · 数学 2019-10-29 Maciej Niebrzydowski

Knotted solutions to electromagnetism and fluid dynamics are investigated, based on relations we find between the two subjects. We can write fluid dynamics in electromagnetism language, but only on an initial surface, or for linear…

高能物理 - 理论 · 物理学 2018-01-17 Daniel W. F. Alves , Carlos Hoyos , Horatiu Nastase , Jacob Sonnenschein

We present a detailed numerical analysis of the effect of a magnetic field on the transport properties of a `small-$N$' one-sided surface disordered wire. When time reversal symmetry is broken due to a magnetic field $B$, we find a strong…

介观与纳米尺度物理 · 物理学 2016-08-16 A. García-Martín , M. Governale , P. Wölfle

In this chapter, we review the Ra\~{n}ada field line solutions of Maxwell's equations in the vacuum, which describe a topologically non-trivial electromagnetic field, as well as their relation with the knot theory. Also, we present a…

经典物理 · 物理学 2020-04-15 Ion V. Vancea

We extend knot contact homology to a theory over the ring $\mathbb{Z}[\lambda^{\pm 1},\mu^{\pm 1}]$, with the invariant given topologically and combinatorially. The improved invariant, which is defined for framed knots in $S^3$ and can be…

几何拓扑 · 数学 2008-06-11 Lenhard Ng

A new type of knot energy is presented via real life experiments involving a thin resilient metallic tube. Knotted in different ways, the device mechanically acquires a uniquely determined (up to isometry) normal form at least when the…

几何拓扑 · 数学 2015-05-20 A. B. Sossinsky