0000000000306921

AUTHOR

Vyron Vellis

0000-0003-2297-7202

showing 4 related works from this author

Quasisymmetric extension on the real line

2018

We give a geometric characterization of the sets $E\subset \mathbb{R}$ that satisfy the following property: every quasisymmetric embedding $f: E \to \mathbb{R}^n$ extends to a quasisymmetric embedding $f:\mathbb{R}\to\mathbb{R}^N$ for some $N\geq n$.

Mathematics::Combinatoricsrelatively connected setsApplied MathematicsGeneral Mathematics010102 general mathematicsta111Extension (predicate logic)Characterization (mathematics)01 natural sciencesCombinatoricsfunktioteoria0103 physical sciencesMathematics::Metric GeometryEmbedding010307 mathematical physics0101 mathematicsReal linequasisymmetric extensionMathematicsProceedings of the American Mathematical Society
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Weak chord-arc curves and double-dome quasisymmetric spheres

2014

Let $\Omega$ be a planar Jordan domain and $\alpha>0$. We consider double-dome-like surfaces $\Sigma(\Omega,t^{\alpha})$ over $\overline{\Omega}$ where the height of the surface over any point $x\in\overline{\Omega}$ equals $\text{dist}(x,\partial\Omega)^{\alpha}$. We identify the necessary and sufficient conditions in terms of $\Omega$ and $\alpha$ so that these surfaces are quasisymmetric to $\mathbb{S}^2$ and we show that $\Sigma(\Omega,t^{\alpha})$ is quasisymmetric to the unit sphere $\mathbb{S}^2$ if and only if it is linearly locally connected and Ahlfors $2$-regular.

Unit sphereChord (geometry)QA299.6-43330C65 30C62Mathematics::Complex VariablesApplied Mathematics010102 general mathematicsdouble-dome-like surfacesMetric Geometry (math.MG)16. Peace & justice01 natural sciencesOmegachord-arc propertyCombinatoricsMathematics - Metric GeometryFOS: Mathematicsquasisymmetric spheresAhlfors 2-regularityMathematics::Metric GeometrySPHERESGeometry and Topology0101 mathematicsahlfors 2-regularityAnalysisMathematics
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Quasisymmetric spheres over Jordan domains

2015

Let $\Omega$ be a planar Jordan domain. We consider double-dome-like surfaces $\Sigma$ defined by graphs of functions of $dist( \cdot ,\partial \Omega)$ over $\Omega$. The goal is to find the right conditions on the geometry of the base $\Omega$ and the growth of the height so that $\Sigma$ is a quasisphere, or quasisymmetric to $\mathbb{S}^2$. An internal uniform chord-arc condition on the constant distance sets to $\partial \Omega$, coupled with a mild growth condition on the height, gives a close-to-sharp answer. Our method also produces new examples of quasispheres in $\mathbb{R}^n$, for any $n\ge 3$.

Applied MathematicsGeneral MathematicsGraph of a functionMetric Geometry (math.MG)16. Peace & justiceOmegaCombinatoricsBase (group theory)Mathematics - Metric GeometryDomain (ring theory)FOS: MathematicsSPHERESConstant (mathematics)Mathematics
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Quasisymmetric extension on the real line

2015

We give a geometric characterization of the sets $E\subset \mathbb{R}$ that satisfy the following property: every quasisymmetric embedding $f: E \to \mathbb{R}^n$ extends to a quasisymmetric embedding $f:\mathbb{R}\to\mathbb{R}^N$ for some $N\geq n$.

funktioteoriarelatively connected setsMathematics::CombinatoricsMathematics - Metric GeometryFOS: MathematicsMathematics::Metric GeometryMetric Geometry (math.MG)quasisymmetric extension30C65
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