Search results for "49Q10"

showing 5 items of 5 documents

Minimality via second variation for microphase separation of diblock copolymer melts

2017

Abstract We consider a non-local isoperimetric problem arising as the sharp interface limit of the Ohta–Kawasaki free energy introduced to model microphase separation of diblock copolymers. We perform a second order variational analysis that allows us to provide a quantitative second order minimality condition. We show that critical configurations with positive second variation are indeed strict local minimizers of the problem. Moreover, we provide, via a suitable quantitative inequality of isoperimetric type, an estimate of the deviation from minimality for configurations close to the minimum in the L 1 {L^{1}} -topology.

49Q10isoperimetric problemsApplied MathematicsGeneral Mathematics010102 general mathematicsSeparation (aeronautics)Mathematical analysisOrder (ring theory)Type (model theory)01 natural sciences010101 applied mathematicsMathematics - Analysis of PDEsinterfacial problemsFOS: MathematicsCopolymercopolymersLimit (mathematics)0101 mathematicsVariational analysisIsoperimetric inequalityTopology (chemistry)Analysis of PDEs (math.AP)Mathematics
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An elementary formula for computing shape derivatives of EFIE system matrix

2012

We derive analytical shape derivative formulas of the system matrix representing electric field integral equation discretized with Raviart-Thomas basis functions. The arising integrals are easy to compute with similar methods as the entries of the original system matrix. The results are compared to derivatives computed with automatic differentiation technique and finite differences, and are found to be in excellent agreement.

65M38 (Primary) 35Q93 49Q10 (Secondary)FOS: MathematicsNumerical Analysis (math.NA)Mathematics - Numerical Analysis
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Quantitative lower bounds to the Euclidean and the Gaussian Cheeger constants

2020

We provide a quantitative lower bound to the Cheeger constant of a set $\Omega$ in both the Euclidean and the Gaussian settings in terms of suitable asymmetry indexes. We provide examples which show that these quantitative estimates are sharp.

Gaussianmedia_common.quotation_subject01 natural sciencesUpper and lower boundsAsymmetryOmegaCombinatoricsSet (abstract data type)Cheeger sets; Cheeger constant; quantitative inequalitiessymbols.namesakeMathematics - Analysis of PDEsEuclidean geometryFOS: MathematicsMathematics::Metric Geometry0101 mathematicsepäyhtälötMathematicsmedia_common49Q10 49Q20 39B62osittaisdifferentiaaliyhtälöt010102 general mathematicsCheeger constantCheeger setsArticlesCheeger constant (graph theory)010101 applied mathematicssymbolsquantitative inequalitiesAnalysis of PDEs (math.AP)Annales Fennici Mathematici
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On the shape of compact hypersurfaces with almost constant mean curvature

2015

The distance of an almost constant mean curvature boundary from a finite family of disjoint tangent balls with equal radii is quantitatively controlled in terms of the oscillation of the scalar mean curvature. This result allows one to quantitatively describe the geometry of volume-constrained stationary sets in capillarity problems.

Mathematics - Differential GeometryMean curvatureOscillationApplied MathematicsGeneral Mathematics010102 general mathematicsMathematical analysisScalar (mathematics)Boundary (topology)TangentMetric Geometry (math.MG)Disjoint sets01 natural sciences010101 applied mathematicsMathematics - Analysis of PDEsMean curvature capillarity theory quantitative estimates Alexandrov theorem.Differential Geometry (math.DG)Mathematics - Metric Geometry49Q10 49Q20 53A10FOS: MathematicsMathematics::Differential Geometry0101 mathematicsConstant (mathematics)Analysis of PDEs (math.AP)Mathematics
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On the regularity of critical and minimal sets of a free interface problem

2015

We study a free interface problem of finding the optimal energy configuration for mixtures of two conducting materials with an additional perimeter penalization of the interface. We employ the regularity theory of linear elliptic equations to study the possible opening angles of Taylor cones and to give a different proof of a partial regularity result by Fan Hua Lin [Calc Var. Partial Differential Equations, 1993].

PhysicsRegularity of minimal surfacesInterface (Java)Applied Mathematicsta111010102 general mathematicsMathematical analysisFree interfaceConical surface01 natural sciences010305 fluids & plasmasMathematics - Analysis of PDEsFree interface0103 physical sciencesFOS: MathematicsTaylor cones0101 mathematicsEnergy (signal processing)49Q10 49N60 74G40Analysis of PDEs (math.AP)
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