6533b852fe1ef96bd12ab60c

RESEARCH PRODUCT

Uniform, Sobolev extension and quasiconformal circle domains

David A. HerronPekka Koskela

subject

Sobolev spacePartial differential equationGeneral MathematicsBounded functionMathematical analysisEquivalence (formal languages)QuasicircleAnalysisMathematicsSobolev spaces for planar domains

description

This paper contributes to the theory of uniform domains and Sobolev extension domains. We present new features of these domains and exhibit numerous relations among them. We examine two types of Sobolev extension domains, demonstrate their equivalence for bounded domains and generalize known sufficient geometric conditions for them. We observe that in the plane essentially all of these domains possess the trait that there is a quasiconformal self-homeomorphism of the extended plane which maps a given domain conformally onto a circle domain. We establish a geometric condition enjoyed by these plane domains which characterizes them among all quasicircle domains having no large and no small boundary components.

https://doi.org/10.1007/bf03041069