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We show that a locally Ahlfors 2-regular and locally linearly locally contractible metric surface is locally quasisymmetrically equivalent to the disk. We also discuss an application of this result to the problem of characterizing surfaces…

Metric Geometry · Mathematics 2007-09-07 Kevin Wildrick

We study planar domains $G$ equipped with a hyperbolic type metric and approximate geodesics that join two points $x,y \in G$ and their lengths. We present an algorithm that enables one to approximate the shortest distance in polygonal…

Metric Geometry · Mathematics 2026-05-26 Shuliang Gao , Anni Hakanen , Antti Rasila , Matti Vuorinen

Quasi-invariant and pseudo-differentiable measures on a Banach space $X$ over a non-Archimedean locally compact infinite field with a non-trivial valuation are defined and constructed. Measures are considered with values in $\bf R$.…

General Mathematics · Mathematics 2007-05-23 Sergey V. Ludkovsky

The present paper is concerned with Lipschitz properties of convex mappings. One considers the general context of mappings defined on an open convex subset $\Omega$ of a locally convex space $X$ and taking values in a locally convex space…

Functional Analysis · Mathematics 2017-01-12 S. Cobzaş

With the advancement of computer technology, there is a surge of interest in effective mapping methods for objects in higher-dimensional spaces. To establish a one-to-one correspondence between objects, higher-dimensional quasi-conformal…

Computational Geometry · Computer Science 2022-06-30 Daoping Zhang , Gary P. T. Choi , Jianping Zhang , Lok Ming Lui

We study harmonic and quasi-harmonic discs in metric spaces admitting a uniformly local quadratic isoperimetric inequality for curves. The class of such metric spaces includes compact Lipschitz manifolds, metric spaces with upper or lower…

Analysis of PDEs · Mathematics 2015-12-04 Alexander Lytchak , Stefan Wenger

Adjoint methods can speed up stellarator optimisation by providing gradient information more efficiently compared to finite-difference evaluations. Adjoint methods are herein applied to vacuum magnetic fields, with objective functions…

Plasma Physics · Physics 2022-02-16 Richard Nies , Elizabeth J. Paul , Stuart R. Hudson , Amitava Bhattacharjee

We present a survey of the many and various elements of the modern higher-dimensional theory of quasiconformal mappings and their wide and varied application. It is unified (and limited) by the theme of the author's interests. Thus we will…

Complex Variables · Mathematics 2013-11-06 Gaven J. Martin

The volume distance from a point p to a convex hypersurface M of the (N+1)-dimensional space is defined as the minimum (N+1)-volume of a region bounded by M and a hyperplane H through the point. This function is differentiable in a…

Differential Geometry · Mathematics 2012-01-10 Marcos Craizer , Ralph C. Teixeira

This article analyzes sublinearly quasisymmetric homeo-morphisms (generalized quasisymmetric mappings), and draws applications to the sublinear large-scale geometry of negatively curved groups and spaces. It is proven that those…

Metric Geometry · Mathematics 2020-03-02 Gabriel Pallier

We study when a metric surface $X$ can be mapped quasisymmetrically onto a circle domain $D\subset\mathbb{C}$ with uniformly relatively separated boundary components. Bonk \cite{Bonk} proved that if $X\subset \hat{\mathbb{C}}$ and the…

Complex Variables · Mathematics 2025-08-26 Hrant Hakobyan , Jonathan Rehmert

We will show that the distance between two minimal hypersurfaces is a Lipschitz continuous supersolution, in the viscosity sense, of a natural elliptic partial differential equation. This not only recovers several well-known properties of…

Differential Geometry · Mathematics 2026-05-12 Tobias Holck Colding , William P. Minicozzi

We prove that if a quasiconvex subset $X$ of a metric space $Y$ has finite Nagata dimension and is Lipschitz $k$-connected or admits Euclidean isoperimetric inequalities up to dimension $k$ for some $k$ then $X$ is isoperimetrically…

Metric Geometry · Mathematics 2021-12-23 Giuliano Basso , Stefan Wenger , Robert Young

We prove a Koebe distortion theorem for the average derivative of a quasiconformal mapping between domains in the sub-Riemannian Heisenberg group $\mathbb{H}_1$. Several auxiliary properties of quasiconformal mappings between subdomains of…

Metric Geometry · Mathematics 2019-05-20 Tomasz Adamowicz , Katrin Fässler , Ben Warhurst

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

The article is devoted to the study of mappings that satisfy the so-called inverse Poletsky inequality. We consider mappings of quasiextremal distance domains, domains with a locally quasiconformal boundary, and domains which are regular in…

Complex Variables · Mathematics 2023-10-03 M. V. Androschuk , O. P. Dovhopiatyi , N. S. Ilkevych , E. A. Sevost'yanov

Theoretical estimates of the convergence rate of many well-known gradient-type optimization methods are based on quadratic interpolation, provided that the Lipschitz condition for the gradient is satisfied. In this article we obtain a…

Optimization and Control · Mathematics 2018-12-18 Fedor S. Stonyakin

We introduce a class of mappings called vertical quasi-isometries and show that branched quasisymmetries $X\to Y$ of Guo and Williams between compact, bounded turning metric doubling spaces admit natural vertically quasi-isometric…

Metric Geometry · Mathematics 2019-12-02 Jeff Lindquist , Pekka Pankka

Uniformly quasiconformally homogeneous domains in $\mathbb{R}^n$ carry a transitive collection of $K$-quasiconformal maps for a fixed $K\geq 1.$ In this paper, we study two questions in this setting. The first is to show that…

Complex Variables · Mathematics 2025-04-30 Alastair Fletcher , Allyson Hahn

We study quasiisometries between negatively curved homogeneous manifolds associated with diagonalizable derivations on Heisenberg algebras. We classify these manifolds up to quasiisometry, and show that all quasiisometries between such…

Group Theory · Mathematics 2015-06-12 Xiangdong Xie