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Conformal mapping may be the best-known topic in complex analysis. Any simply connected nonempty domain $\Omega$ in the complex plane ${{\mathbb{C}}}$ (assuming $\Omega\ne {{\mathbb{C}}}$) can be mapped bijectively to the unit disk by an…

Complex Variables · Mathematics 2025-07-22 Lloyd N. Trefethen

We present a $(1+\epsilon)$-approximation algorithm running in $O(f(\epsilon)\cdot n \log^4 n)$ time for finding the diameter of an undirected planar graph with non-negative edge lengths.

Data Structures and Algorithms · Computer Science 2013-04-23 Oren Weimann , Raphael Yuster

We study metric spaces defined via a conformal weight, or more generally a measurable Finsler structure, on a domain $\Omega \subset \mathbb{R}^2$ that vanishes on a compact set $E \subset \Omega$ and satisfies mild assumptions. Our main…

Metric Geometry · Mathematics 2020-06-08 Toni Ikonen , Matthew Romney

We give a $(1+\epsilon)$-approximate distance oracle with $O(1)$ query time for an undirected planar graph $G$ with $n$ vertices and non-negative edge lengths. For $\epsilon>0$ and any two vertices $u$ and $v$ in $G$, our oracle gives a…

Data Structures and Algorithms · Computer Science 2017-06-13 Qian-Ping Gu , Gengchun Xu

Consider discrete conformal maps defined on the basis of two conformally equivalent triangle meshes, that is edge lengths are related by scale factors associated to the vertices. Given a smooth conformal map $f$, we show that it can be…

Complex Variables · Mathematics 2020-02-26 Ulrike Bücking

We study approximation algorithms for the following geometric version of the maximum coverage problem: Let P be a set of n weighted points in the plane. We want to place m a * b rectangles such that the sum of the weights of the points in P…

Computational Geometry · Computer Science 2015-05-12 Jian Li , Haitao Wang , Bowei Zhang , Ningye Zhang

Given a vertex-labeled graph, each vertex $v$ is attached with a label from a set of labels. The vertex-label query desires the length of the shortest path from the given vertex to the set of vertices with the given label. We show how to…

Data Structures and Algorithms · Computer Science 2012-02-01 Mingfei Li , Christoffer Ma , Li Ning

We study conformal quantities at generic parameters with respect to the harmonic measure on the boundary of the connectedness loci ${\cal M}_d$ for unicritical polynomials $f_c(z)=z^d+c$. It is known that these parameters are structurally…

Dynamical Systems · Mathematics 2019-05-07 Jacek Graczyk , Grzegorz Świątek

Let $P$ and $Q$ be two simple polygons in the plane of total complexity $n$, each of which can be decomposed into at most $k$ convex parts. We present an $(1-\varepsilon)$-approximation algorithm, for finding the translation of $Q$, which…

Computational Geometry · Computer Science 2014-06-24 Sariel Har-Peled , Subhro Roy

Given a set $\mathcal{P}$ of $h$ pairwise disjoint simple polygonal obstacles in $\mathbb{R}^2$ defined with $n$ vertices, we compute a sketch $\Omega$ of $\mathcal{P}$ whose size is independent of $n$, depending only on $h$ and the input…

Computational Geometry · Computer Science 2019-09-17 R Inkulu , Sanjiv Kapoor

Roughly speaking, let us say that a map between metric spaces is large scale conformal if it maps packings by large balls to large quasi-balls with limited overlaps. This quasi-isometry invariant notion makes sense for finitely generated…

Differential Geometry · Mathematics 2017-11-28 Pierre Pansu

We construct, for every \(0<k<1\), a bounded globally univalent harmonic mapping \[ f=h+\overline g \colon \D\to\C \] such that \[ |g'(z)|\le k|h'(z)|,\qquad z\in\D, \] while the analytic part \(h\) is unbounded. The construction is based…

Complex Variables · Mathematics 2026-05-05 David Kalaj

We consider planar $\sigma$-harmonic mappings, that is mappings $U$ whose components $u^1$ and $u^2$ solve a divergence structure elliptic equation ${\rm div} (\sigma \nabla u^i)=0$, for $i=1,2$. We investigate whether a locally invertible…

Analysis of PDEs · Mathematics 2014-12-16 Giovanni Alessandrini , Vincenzo Nesi

We study approximation algorithms for the following geometric version of the maximum coverage problem: Let $\mathcal{P}$ be a set of $n$ weighted points in the plane. Let $D$ represent a planar object, such as a rectangle, or a disk. We…

Computational Geometry · Computer Science 2017-12-08 Kai Jin , Jian Li , Haitao Wang , Bowei Zhang , Ningye Zhang

By the Riemann-mapping theorem, one can bijectively map the interior of an $n$-gon $P$ to that of another $n$-gon $Q$ conformally. However, (the boundary extension of) this mapping need not necessarily map the vertices of $P$ to those $Q$.…

Differential Geometry · Mathematics 2014-01-27 Mayank Goswami , Xianfeng Gu , Vamsi P. Pingali , Gaurish Telang

Thorup [FOCS'01, JACM'04] and Klein [SODA'01] independently showed that there exists a $(1+\epsilon)$-approximate distance oracle for planar graphs with $O(n (\log n)\epsilon^{-1})$ space and $O(\epsilon^{-1})$ query time. While the…

Data Structures and Algorithms · Computer Science 2022-07-13 Hung Le

A $(1+\epsilon)$-approximate distance oracle of an edge-weighted graph is a data structure that returns an approximate shortest path distance between any two query vertices up to a $(1+\epsilon)$ factor. Thorup (FOCS 2001, JACM 2004) and…

Data Structures and Algorithms · Computer Science 2021-11-08 Hung Le , Christian Wulff-Nilsen

Let $\mathcal{P}$ be a simple polygon with $m$ vertices and let $P$ be a set of $n$ points inside $\mathcal{P}$. We prove that there exists, for any $\varepsilon>0$, a set $\mathcal{C} \subset P$ of size $O(1/\varepsilon^2)$ such that the…

Computational Geometry · Computer Science 2024-03-08 Mark de Berg , Leonidas Theocharous

Conformable derivatives provide a fractional-looking calculus that remains local and admits a simple representation through classical derivatives with explicit weights. In this paper we develop a systematic operator-theoretic perspective…

Analysis of PDEs · Mathematics 2026-01-08 Mohamed Khoulane , Aziz El Ghazouani , M'hamed El Omari

A maximal $\varepsilon$-near perfect matching is a maximal matching which covers at least $(1-\varepsilon)|V(G)|$ vertices. In this paper, we study the number of maximal near perfect matchings in generalized quasirandom and dense graphs. We…

Combinatorics · Mathematics 2019-02-07 Yifan Jing , Akbar Rafiey
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