Search results for "partial differential equation"

showing 10 items of 326 documents

Existence and uniqueness for the Prandtl equations

2001

International audience; Under the hypothesis of analyticity of the data with respect to the tangential variable we prove the existence and uniqueness of the mild solution of Prandtl boundary layer equation. This can be considered an improvement of the results of [8] as we do not require analyticity with respect to the normal variable. (C) 2001 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.

Partial differential equation010102 general mathematicsPrandtl numberMathematical analysisGeneral Medicine01 natural sciencesEuler equations010101 applied mathematicssymbols.namesakeBoundary layer[MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph]symbolsUniqueness0101 mathematicsConvection–diffusion equationNavier–Stokes equationsVariable (mathematics)Mathematics
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Quasi-linear diffusion equations with gradient terms and L1 data

2004

Abstract In this article we study the following quasi-linear parabolic problem: u t − Δ u+|u| β−2 u| ∇ u| q =|u| α−2 u| ∇ u| p in Ω×]0,T[, u(x,t)=0 on ∂Ω×]0,T[, u(x,0)=u 0 (x) in Ω, where Ω is a bounded open set of R N and T>0. We prove that if α,β>1, 0⩽p u 0 ∈L 1 (Ω) .

Partial differential equationApplied MathematicsBounded functionMathematical analysisOpen setParabolic problemQuasi linearDiffusion (business)AnalysisMathematicsNonlinear Analysis: Theory, Methods & Applications
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Formation of Coherent Structures in Kolmogorov Flow with Stratification and Drag

2014

We study a weakly stratified Kolmogorov flow under the effect of a small linear drag. We perform a linear stability analysis of the basic state. We construct the finite dimensional dynamical system deriving from the truncated Fourier mode approximation. Using the Reynolds number as bifurcation parameter we build the corresponding diagram up to Re=100. We observe the coexistence of three coherent structures.

Partial differential equationApplied MathematicsDiagramMathematical analysisReynolds numberDynamical systemPhysics::Fluid DynamicsLinear stability analysisymbols.namesakeFourier transformBifurcation theoryDragsymbolsBifurcation theoryEquilibriaTruncated Navier-Stokes equationsSettore MAT/07 - Fisica MatematicaBifurcationMathematics
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Singular integrals, analytic capacity and rectifiability

1997

In this survey we study some interplay between classical complex analysis (removable sets for bounded analytic functions), harmonic analysis (singular integrals), and geometric measure theory (rectifiability).

Partial differential equationApplied MathematicsGeneral MathematicsMathematical analysisSingular integralGeometric measure theorysymbols.namesakeSingular solutionFourier analysisBounded functionsymbolsAnalytic capacityAnalysisMathematicsAnalytic functionThe Journal of Fourier Analysis and Applications
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A free boundary problem stemmed from combustion theory. Part II: Stability, instability and bifurcation results

2002

AbstractWe deal with a free boundary problem, depending on a real parameter λ, in a infinite strip in R2, providing stability, instability and bifurcation.

Partial differential equationApplied MathematicsMathematical analysisLinearizationSaddle-node bifurcationFully nonlinear elliptic and parabolic systemsBifurcation diagramFree boundary problemsInstabilityTranscritical bifurcationLinearizationFree boundary problemBifurcationStabilityBifurcationAnalysisMathematicsJournal of Mathematical Analysis and Applications
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On the Prandtl Boundary Layer Equations in Presence of Corner Singularities

2014

In this paper we prove the well-posedness of the Prandtl boundary layer equations on a periodic strip when the initial and the boundary data are not assigned to be compatible.

Partial differential equationApplied MathematicsPrandtl numberMathematics::Analysis of PDEsGeometryMixed boundary conditionBoundary layer thicknessRobin boundary conditionBoundary layersymbols.namesakeBoundary layerBlasius boundary layerAnalytic normsymbolsBoundary value problemIncompatible dataSettore MAT/07 - Fisica MatematicaMathematicsActa Applicandae Mathematicae
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A note on the analytic solutions of the Camassa-Holm equation

2005

Abstract In this Note we are concerned with the well-posedness of the Camassa–Holm equation in analytic function spaces. Using the Abstract Cauchy–Kowalewski Theorem we prove that the Camassa–Holm equation admits, locally in time, a unique analytic solution. Moreover, if the initial data is real analytic, belongs to H s ( R ) with s > 3 / 2 , ‖ u 0 ‖ L 1 ∞ and u 0 − u 0 x x does not change sign, we prove that the solution stays analytic globally in time. To cite this article: M.C. Lombardo et al., C. R. Acad. Sci. Paris, Ser. I 341 (2005).

Partial differential equationCamassa–Holm equationFunction spaceComplex singularitieMathematical analysisGeneral MedicineNonlinear Sciences::Exactly Solvable and Integrable SystemsCauchy–Kowalewski TheoremCamassa–Holm equationAnalytic solutionAnalytic functionMathematicsMathematical physicsSign (mathematics)
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Large Number Asymptotics for Two-Component Systems with Self-Consistent Coupling

2014

We shall consider the large number asymptotics of particle models for partial differential equations describing two component mixtures with simplest kind of self-consistent couplings. We shall recall in particular two examples related to different classes of models, the first one having both particle-like components and the second one having only one particle-like component (the other being described as a fluid); for these examples, different techniques on the probabilistic and analytic point of view are to be used to rigorously prove the convergence to a limit of the self-consistent terms in a “mean-field”-like asymptotics. The two models were analysed resp. in Bernardin and Ricci (Kinet R…

Partial differential equationComponent (thermodynamics)Numerical analysisConvergence (routing)Probabilistic logicApplied mathematicsHeat equationLimit (mathematics)PreprintTwo-component systems Interacting particle systems large number limit self--consistent couplingMathematics
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On superconvergence techniques

1987

A brief survey with a bibliography of superconvergence phenomena in finding a numerical solution of differential and integral equations is presented. A particular emphasis is laid on superconvergent schemes for elliptic problems in the plane employing the finite element method.

Partial differential equationComputer Science::Computational Engineering Finance and SciencePlane (geometry)Applied MathematicsMathematical analysisBibliographySuperconvergenceComputer Science::Numerical AnalysisIntegral equationFinite element methodDifferential (mathematics)Mathematics::Numerical AnalysisMathematicsActa Applicandae Mathematicae
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Milton’s conjecture on the regularity of solutions to isotropic equations

2003

Abstract We present examples showing that the threshold for the integrability of the gradient of solutions to isotropic equations is 2K/(K−1). The main tools are p-laminates and Beltrami Operators.

Partial differential equationConjectureApplied MathematicsBeltrami operatorMathematical analysisIsotropyHölder conditionMathematical PhysicsAnalysisMathematicsAnnales de l'Institut Henri Poincaré C, Analyse non linéaire
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