English
Related papers

Related papers: On intersections of closed curves on surfaces

200 papers

A numerical scheme is presented for solving the Helmholtz equation with Dirichlet or Neumann boundary conditions on piecewise smooth open curves, where the curves may have corners and multiple junctions. Existing integral equation methods…

Numerical Analysis · Mathematics 2024-11-11 Johan Helsing , Shidong Jiang

We consider the local sensitivity of least-squares formulations of inverse problems. The sets of inputs and outputs of these problems are assumed to have the structures of Riemannian manifolds. The problems we consider include the…

Numerical Analysis · Mathematics 2022-09-02 Paul Breiding , Nick Vannieuwenhoven

Given two maps f_1, f_2 : M^m \longrightarrow N^n between manifolds of the indicated arbitrary dimensions, when can they be deformed away from one another? More generally: what is the minimum number MCC (f_1, f_2) of pathcomponents of the…

Algebraic Topology · Mathematics 2007-05-23 Ulrich Koschorke

We generalize two classical formulas for complete intersection curves by introducing the the complete intersection discrepancy of a curve as a correction term. The first is a well-known multiplicity formula in singularity theory, due to…

Algebraic Geometry · Mathematics 2026-04-07 Andrei Benguş-Lasnier , Antoni Rangachev

As a consequence of our recently established generalized Schmidt's subspace theorem for closed subschemes in general position, we prove a degeneracy theorem for integral points on the complement of a union of nef effective divisors. A novel…

Number Theory · Mathematics 2020-06-23 Gordon Heier , Aaron Levin

A longstanding avenue of research in orientable surface topology is to create and enumerate collections of curves in surfaces with certain intersection properties. We look for similar collections of curves in non-orientable surfaces. A…

Geometric Topology · Mathematics 2023-04-19 Sarah Ruth Nicholls , Nancy Scherich , Julia Shneidman

We estimate from below the number of lines meeting each of given 4 disjoint smooth closed curves in a given cyclic order in the real projective 3-space and in a given linear order in the Euclidean 3-space. Similarly, we estimate the number…

Geometric Topology · Mathematics 2007-05-23 Julia Viro

In classical fixed point and coincidence theory the notion of Nielsen numbers has proved to be extremely fruitful. We extend it to pairs (f_1,f_2) of maps between manifolds of arbitrary dimensions, using nonstabilized normal bordism theory…

Algebraic Topology · Mathematics 2009-03-01 Ulrich Koschorke

In classical fixed point and coincidence theory the notion of Nielsen numbers has proved to be extremely fruitful. Here we extend it to pairs (f_1, f_2) of maps between manifolds of arbitrary dimensions. This leads to estimates of the…

Algebraic Topology · Mathematics 2007-05-23 Ulrich Koschorke

On an orientable surface $S$, consider a collection $\Gamma$ of closed curves. The (geometric) intersection number $i_S(\Gamma)$ is the minimum number of self-intersections that a collection $\Gamma'$ can have, where $\Gamma'$ results from…

Computational Geometry · Computer Science 2024-02-08 Loïc Dubois

Weak and strong coloring numbers are generalizations of the degeneracy of a graph, where for each natural number $k$, we seek a vertex ordering such every vertex can (weakly respectively strongly) reach in $k$ steps only few vertices with…

Combinatorics · Mathematics 2021-04-08 Zdeněk Dvořák , Jakub Pekárek , Torsten Ueckerdt , Yelena Yuditsky

It is known since the work of Frankel that two compactly immersed minimal hypersurfaces in a manifold with positive Ricci curvature must have an intersection point. Several generalizations of this result can be found in the literature, for…

Differential Geometry · Mathematics 2020-04-20 Renan Assimos

Minimal surfaces with planar curvature lines are classical geometric objects, having been studied since the late 19th century. In this paper, we revisit the subject from a different point of view. After calculating their metric functions…

Differential Geometry · Mathematics 2018-05-16 Joseph Cho , Yuta Ogata

If two Jordan curves in the plane have precisely one point in common, and there they do not properly cross, then the common point is called a {\em touching point}. The main result of this paper is a Crossing Lemma for simple curves: Let $X$…

Combinatorics · Mathematics 2017-08-08 János Pach , Natan Rubin , Gábor Tardos

The classical Whitney formula relates the number of times an oriented plane curve cuts itself to its rotation number and the index of a base point. In this paper we generalize Whitney's formula to curves on an oriented punctured surface. To…

Geometric Topology · Mathematics 2019-02-06 Yurii Burman , Michael Polyak

A fast algorithm for counting intersections of two normal curves on a triangulated surface is proposed. It yields a convenient way for treating mapping class groups of punctured surfaces by presenting mapping classes by matrices, and the…

Geometric Topology · Mathematics 2021-10-12 Ivan Dynnikov

Many classical objects on a surface S can be interpreted as cross-ratio functions on the circle at infinity of the universal covering. This includes closed curves considered up to homotopy, metrics of negative curvature considered up to…

Complex Variables · Mathematics 2018-08-02 Francis Bonahon , Dragomir Saric

We establish that the intersection number between the horizontal foliations of any two finite-area holomorphic quadratic differentials on an arbitrary Riemann surface is finite. Our main result shows that the intersection number is jointly…

Complex Variables · Mathematics 2025-06-19 Dragomir Saric , Taro Shima

In this paper we continue to study (`strong') Nielsen coincidence numbers (which were introduced recently for pairs of maps between manifolds of arbitrary dimensions) and the corresponding minimum numbers of coincidence points and…

Algebraic Topology · Mathematics 2009-04-12 Ulrich Koschorke

We study the Dirichlet problem for minimal surface systems in arbitrary dimension and codimension via mean curvature flow, and obtain the existence of minimal graphs over arbitrary mean convex bounded $C^2$ domains for a large class of…

Differential Geometry · Mathematics 2023-12-27 Qi Ding , J. Jost , Y. L. Xin