0000000001325969

AUTHOR

Päivi Lammi

showing 3 related works from this author

Compactness of a conformal boundary of the Euclidean unit ball

2011

We study conformal metrics d‰ on the Euclidean unit ball B n : We assume that either the density ‰ associated with the metric d‰ satisfies a logarithmic volume growth condition for small balls or that ‰ satisfies a Harnack inequality and a suitable sub-Euclidean volume growth condition. We prove that the ‰-boundary @‰ B n is homeomorphic to S ni1 if and only if @‰ B n is compact. In the planar case, the compactness of @‰ B 2 is further equivalent to local connectivity of the ‰-boundary together with the boundedness of (B 2 ;d‰):

CombinatoricsUnit sphereCompact spaceLogarithmGeneral MathematicsMathematical analysisEuclidean geometryMetric (mathematics)Boundary (topology)Conformal mapMathematicsHarnack's inequalityAnnales Academiae Scientiarum Fennicae Mathematica
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Quasihyperbolic boundary condition: Compactness of the inner boundary

2011

We prove that if a metric space satisfies a suitable growth condition in the quasihyperbolic metric and the Gehring–Hayman theorem in the original metric, then the inner boundary of the space is homeomorphic to the Gromov boundary. Thus, the inner boundary is compact. peerReviewed

Gromov boundaryquasihyperbolic metricMathematics::Complex VariablesGeneral Mathematicsgrowth conditionMathematical analysisBoundary (topology)Mixed boundary conditionGromov-reuna30C65Gromov boundaryMetric spaceCompact spaceGromov hyperbolicityGromov-hyperbolisuusMetric (mathematics)Neumann boundary conditionMathematics::Metric Geometrykasvuehtokvasihyperbolinen metriikkaBoundary value problemMathematicsIllinois Journal of Mathematics
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Gromov hyperbolicity and quasihyperbolic geodesics

2014

We characterize Gromov hyperbolicity of the quasihyperbolic metric space (\Omega,k) by geometric properties of the Ahlfors regular length metric measure space (\Omega,d,\mu). The characterizing properties are called the Gehring--Hayman condition and the ball--separation condition. peerReviewed

Gromov hyperbolicityMathematics::Complex Variablesquasihyperbolic metricMathematics::Metric GeometryGehring-Hayman inequality
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