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A new definition of a fractional derivative has recently been developed, making use of a fractional Dirac delta function as its integral kernel. This derivative allows for the definition of a distributional fractional derivative, and as…

Classical Analysis and ODEs · Mathematics 2018-05-16 Evan Camrud

In this paper the approximation of Dirac operators with general $\delta$-shell potentials supported on $C^2$-curves in $\mathbb{R}^2$ or $C^2$-surfaces in $\mathbb{R}^3$, which may be bounded or unbounded, is studied. It is shown under…

Spectral Theory · Mathematics 2025-07-03 Jussi Behrndt , Markus Holzmann , Christian Stelzer

The purpose of this article is to find a family of curves parametrized by arc length and that depend on an angular function and an intrinsic fraction function, which is defined as the quotient between torsion and curvature. We find for this…

Differential Geometry · Mathematics 2017-12-07 Héctor Efrén Guerrero Mora

We introduce one dimensional sets to help describe and constrain the integral curves of an $n$ dimensional dynamical system. These curves provide more information about the system than the zero-dimensional sets (fixed points) do. In fact,…

Chaotic Dynamics · Physics 2012-01-23 R. Gilmore , Jean-Marc Ginoux , Timothy Jones , C. Letellier , U. S. Freitas

We construct a continuously differentiable curve in the plane that can be covered by a collection of lines such that every line intersects the curve at a single point and the union of the lines has Hausdorff dimension 1. We show that for…

Metric Geometry · Mathematics 2024-01-29 Tamás Keleti , James Cumberbatch , Jialin Zhang

The electric or magnetic field of an ideal dipole is known to have a Dirac delta function at the origin. The usual textbook derivation of this delta function is rather ad hoc and cannot be used to calculate the delta-function structure for…

Classical Physics · Physics 2017-01-26 Edward Parker

In this article we consider the length functional defined on the space of immersed planar curves. The $L^2(ds)$ Riemannian metric gives rise to the curve shortening flow as the gradient flow of the length functional. Motivated by the…

Differential Geometry · Mathematics 2021-03-04 Philip Schrader , Glen Wheeler , Valentina-Mira Wheeler

We demonstrate how to make the coordinate transformation or change of variables from Cartesian coordinates to curvilinear coordinates by making use of a convolution of a function with Dirac delta functions whose arguments are determined by…

General Physics · Physics 2020-12-18 Dohyun Kim , June-Haak Ee , Chaehyun Yu , Jungil Lee

To an ideal in $\mathbb{C}[x,y]$ one can associate a topological zeta function. This is an extension of the topological zeta function associated to one polynomial. But in this case we use a principalization of the ideal instead of an…

Algebraic Geometry · Mathematics 2007-11-21 Lise Van Proeyen , Willem Veys

We derive pointwise curvature estimates for graphical mean curvature flows in higher codimensions. To the best of our knowledge, this is the first such estimates without assuming smallness of first derivatives of the defining map. An…

Differential Geometry · Mathematics 2014-12-03 Knut Smoczyk , Mao-Pei Tsui , Mu-Tao Wang

We propose a notion of discrete elastic and area-constrained elastic curves in 2-dimensional space forms. Our definition extends the well-known discrete Euclidean curvature equation to space forms and reflects various geometric properties…

Differential Geometry · Mathematics 2025-01-24 Tim Hoffmann , Jannik Steinmeier , Gudrun Szewieczek

In this paper we present geometry of some curves in Taxicab metric. All curves of second order and trifocal ellipse in this metric are presented. Area and perimeter of some curves are also defined.

History and Overview · Mathematics 2019-10-15 Maja Petrovic , Branko Malesevic , Bojan Banjac , Ratko Obradovic

${\cal U}$ntil now the representation (i.e. plotting) of curve in Parallel Coordinates is constructed from the point $\leftrightarrow$ line duality. The result is a ``line-curve'' which is seen as the envelope of it's tangents. Usually this…

Other Computer Science · Computer Science 2007-05-23 Zur Izhakian

We give an explicit formula for the subalgebra zeta function of a general 3-dimensional Lie algebra over the p-adic integers $\mathbb{Z}_p$. To this end, we associate to such a Lie algebra a ternary quadratic form over $\mathbb{Z}_p$. The…

Group Theory · Mathematics 2007-10-11 Benjamin Klopsch , Christopher Voll

Two approaches for the efficient rational approximation of the Fermi-Dirac function are discussed: one uses the contour integral representation and conformal mapping and the other is based on a version of the multipole representation of the…

Numerical Analysis · Mathematics 2009-12-14 Lin Lin , Jianfeng Lu , Lexing Ying , E Weinan

We introduce the Frenet theory of curves in dual space $\d^3$. After defining the curvature and the torsion of a curve, we classify all curves in dual plane with constant curvature. We also establish the fundamental theorem of existence in…

Differential Geometry · Mathematics 2024-12-02 Rafael López

As an outgrowth of our investigation of non-regular spaces within the context of quantum gravity and non-commutative geometry, we develop a graph Hilbert space framework on arbitrary (infinite) graphs and use it to study spectral properties…

Mathematical Physics · Physics 2016-09-07 Manfred Requardt

Possibilities for defining the radial derivative of the delta distribution $\delta(\underline{x})$ in the setting of spherical coordinates are explored. This leads to the introduction of a new class of continuous linear functionals similar…

Classical Analysis and ODEs · Mathematics 2017-08-24 Fred Brackx , Frank Sommen , Jasson Vindas

The boundary of the convex hull of a compact algebraic curve in real 3-space defines a real algebraic surface. For general curves, that boundary surface is reducible, consisting of tritangent planes and a scroll of stationary bisecants. We…

Algebraic Geometry · Mathematics 2011-01-19 Kristian Ranestad , Bernd Sturmfels

The purpose of this paper is to study low degree points on plane curves. We prove results analogous to those of Debarre and Klassen for singular plane curves with a finite number $\delta$ of ordinary nodes/cusps, where $\delta$ is bounded…