0000000000199902

AUTHOR

Debanjan Nandi

showing 2 related works from this author

Accessible parts of boundary for simply connected domains

2018

For a bounded simply connected domain $\Omega\subset\mathbb{R}^2$, any point $z\in\Omega$ and any $0<\alpha<1$, we give a lower bound for the $\alpha$-dimensional Hausdorff content of the set of points in the boundary of $\Omega$ which can be joined to $z$ by a John curve with a suitable John constant depending only on $\alpha$, in terms of the distance of $z$ to $\partial\Omega$. In fact this set in the boundary contains the intersection $\partial\Omega_z\cap\partial\Omega$ of the boundary of a John sub-domain $\Omega_z$ of $\Omega$, centered at $z$, with the boundary of $\Omega$. This may be understood as a quantitative version of a result of Makarov. This estimate is then applied to obta…

General MathematicsBoundary (topology)30C35 26D1501 natural sciencesUpper and lower boundsOmegaDomain (mathematical analysis)CombinatoricsfunktioteoriaHardy inequality0103 physical sciencesSimply connected spaceClassical Analysis and ODEs (math.CA)FOS: MathematicsComplex Variables (math.CV)0101 mathematicsepäyhtälötMathematicsPointwiseMathematics - Complex VariablesApplied Mathematics010102 general mathematicsta111simply connected domainsMathematics - Classical Analysis and ODEsBounded functionContent (measure theory)010307 mathematical physicsJohn domainsProceedings of the American Mathematical Society
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A Density Result for Homogeneous Sobolev Spaces on Planar Domains

2018

We show that in a bounded simply connected planar domain $\Omega$ the smooth Sobolev functions $W^{k,\infty}(\Omega)\cap C^\infty(\Omega)$ are dense in the homogeneous Sobolev spaces $L^{k,p}(\Omega)$.

Pure mathematicsMathematics::Analysis of PDEs01 natural sciencesPotential theoryDomain (mathematical analysis)010104 statistics & probabilityPlanartiheysSimply connected spaceClassical Analysis and ODEs (math.CA)FOS: Mathematics46E350101 mathematicsMathematicsMathematics::Functional AnalysisFunctional analysis010102 general mathematicshomogeneous Sobolev spaceSobolev spaceFunctional Analysis (math.FA)Sobolev spaceMathematics - Functional AnalysisHomogeneousMathematics - Classical Analysis and ODEsBounded functionAnalysis
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