Search results for " equations"

showing 10 items of 783 documents

On time-harmonic Maxwell equations with nonhomogeneous conductivities : Solvability and FE-approximation

1989

The solvability of time-harmonic Maxwell equations in the 3D-case with non­homogeneous conductivities is considered by adapting Sobolev space technique and variational formulation of the probJem in question. Moreover, a finite element approximation is presented in the 3D·case together with an error estimate in the energy norm. Some remarks are given to the 2D-problem arising from geophysics. peerReviewed

msc:35R05msc:65Z05msc:35Q20solution theory [keyword]msc:35Q99finite element approximation [keyword]msc:65N30time-harmonic Maxwell equations [keyword]non-homogeneous conductivities [keyword]error estimation [keyword]numerical experiments [keyword]msc:65N15three- dimensional problem [keyword]msc:78A25
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On a nonlinear Schrödinger equation for nucleons in one space dimension

2021

We study a 1D nonlinear Schrödinger equation appearing in the description of a particle inside an atomic nucleus. For various nonlinearities, the ground states are discussed and given in explicit form. Their stability is studied numerically via the time evolution of perturbed ground states. In the time evolution of general localized initial data, they are shown to appear in the long time behaviour of certain cases.

numerical studySpace dimensionNonlinear Schrö010103 numerical & computational mathematicsNonlinear Schrödinger equations01 natural sciencesStability (probability)symbols.namesakeMathematics - Analysis of PDEs[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]Mathematics - Numerical Analysis0101 mathematics[MATH]Mathematics [math]dinger equationsNonlinear Schrödinger equationMathematicsMSC 35Q55 35C08 65M70Numerical AnalysisApplied Mathematics010102 general mathematicsTime evolutionground statesComputational MathematicsClassical mechanicsModeling and SimulationAtomic nucleussymbolsParticleNucleonAnalysis[MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
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Equivalence of viscosity and weak solutions for the normalized $p(x)$-Laplacian

2018

We show that viscosity solutions to the normalized $p(x)$-Laplace equation coincide with distributional weak solutions to the strong $p(x)$-Laplace equation when $p$ is Lipschitz and $\inf p>1$. This yields $C^{1,\alpha}$ regularity for the viscosity solutions of the normalized $p(x)$-Laplace equation. As an additional application, we prove a Rad\'o-type removability theorem.

osittaisdifferentiaaliyhtälöt35J60 35D40 35D30Pure mathematicsApplied Mathematics010102 general mathematicsLipschitz continuity01 natural sciences010101 applied mathematicsViscosityMathematics - Analysis of PDEspartial differential equationsFOS: Mathematics0101 mathematicsLaplace operatorEquivalence (measure theory)AnalysisMathematicsAnalysis of PDEs (math.AP)
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On the local and global regularity of tug-of-war games

2018

This thesis studies local and global regularity properties of a stochastic two-player zero-sum game called tug-of-war. In particular, we study value functions of the game locally as well as globally, that is, close to the boundaries of the game domains. Furthermore, we formulate a continuous time stochastic differential game and discuss, among other things, the equicontinuity of the families of value functions. The main motivation is to understand the properties of the games on their own right. As applications, we obtain an existence and a regularity result for a nonlinear elliptic p-Laplace type partial differential equation and a characterization of the solution to a parabolic p-Laplace typ…

osittaisdifferentiaaliyhtälötComputer Science::Computer Science and Game Theoryregularitytug-of-war gamespartial differential equationspeliteoriastochastic gamesstokastiset prosessit
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Gradient walks and $p$-harmonic functions

2017

osittaisdifferentiaaliyhtälötMarkov chainApplied MathematicsGeneral Mathematicsta111010102 general mathematics01 natural sciences010101 applied mathematicsHarmonic functionpartial differential equationsstochastic processesStatistical physics0101 mathematicsstokastiset prosessitMathematicsProceedings of the American Mathematical Society
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C1,α-regularity for variational problems in the Heisenberg group

2017

We study the regularity of minima of scalar variational integrals of $p$-growth, $1<p<\infty$, in the Heisenberg group and prove the H\"older continuity of horizontal gradient of minima.

osittaisdifferentiaaliyhtälötNumerical AnalysisregularityHeisenberg groupsApplied Mathematicsp-Laplacian010102 general mathematicsScalar (mathematics)subelliptic equationsHölder condition01 natural sciences35H20 35J70010101 applied mathematicsMaxima and minimaMathematics - Analysis of PDEsweak solutionsPhysics::Atomic and Molecular Clustersp-LaplacianHeisenberg group0101 mathematicsAnalysisMathematical physicsMathematicsAnalysis &amp; PDE
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Nonlinear Liouville Problems in a Quarter Plane

2016

We answer affirmatively the open problem proposed by Cabr\'e and Tan in their paper "Positive solutions of nonlinear problems involving the square root of the Laplacian" (see Adv. Math. {\bf 224} (2010), no. 5, 2052-2093).

osittaisdifferentiaaliyhtälötPlane (geometry)General MathematicsOpen problemta111010102 general mathematicsMathematical analysis35B09 35B53 35J60Quarter (United States coin)01 natural sciencesNonlinear systemMathematics - Analysis of PDEsSquare root0103 physical sciencesFOS: Mathematicspartial differential equations010307 mathematical physics0101 mathematicsLaplace operatorAnalysis of PDEs (math.AP)MathematicsInternational Mathematics Research Notices
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On the regularity of very weak solutions for linear elliptic equations in divergence form

2020

AbstractIn this paper we consider a linear elliptic equation in divergence form $$\begin{aligned} \sum _{i,j}D_j(a_{ij}(x)D_i u )=0 \quad \hbox {in } \Omega . \end{aligned}$$ ∑ i , j D j ( a ij ( x ) D i u ) = 0 in Ω . Assuming the coefficients $$a_{ij}$$ a ij in $$W^{1,n}(\Omega )$$ W 1 , n ( Ω ) with a modulus of continuity satisfying a certain Dini-type continuity condition, we prove that any very weak solution $$u\in L^{n'}_\mathrm{loc}(\Omega )$$ u ∈ L loc n ′ ( Ω ) of (0.1) is actually a weak solution in $$W^{1,2}_\mathrm{loc}(\Omega )$$ W loc 1 , 2 ( Ω ) .

osittaisdifferentiaaliyhtälötPure mathematicsvery weak solutionsApplied MathematicsWeak solution010102 general mathematicselliptic equations01 natural sciencesOmegaModulus of continuity010101 applied mathematicsElliptic curve0101 mathematicsDivergence (statistics)AnalysisMathematics
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Asymptotic mean value formulas for parabolic nonlinear equations

2021

In this paper we characterize viscosity solutions to nonlinear parabolic equations (including parabolic Monge–Ampère equations) by asymptotic mean value formulas. Our asymptotic mean value formulas can be interpreted from a probabilistic point of view in terms of dynamic programming principles for certain two-player, zero-sum games. peerReviewed

osittaisdifferentiaaliyhtälötasymptotic mean value formulasparabolic nonlinear equationsMathematics - Analysis of PDEsviscosity solutionsGeneral MathematicsFOS: MathematicsMathematics::Analysis of PDEsparabolic Monge–Ampère equationsAnalysis of PDEs (math.AP)
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Shape optimization utilizing consistent sensitivities

2010

osittaisdifferentiaaliyhtälötmatemaattinen optimointisensitivity analysisoptimointimuotoilumuodon optimointishape optimizationcomputer simulationpartial differential equationsherkkyysanalyysisimulointialgoritmic differentiationsimulointiohjelmistoautomaattinen derivointitietojenkäsittely
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