Search results for "Mathematics::Analysis of PDEs"

showing 10 items of 179 documents

Homoclinic Solutions of Nonlinear Laplacian Difference Equations Without Ambrosetti-Rabinowitz Condition

2021

The aim of this paper is to establish the existence of at least two non-zero homoclinic solutions for a nonlinear Laplacian difference equation without using Ambrosetti-Rabinowitz type-conditions. The main tools are mountain pass theorem and Palais-Smale compactness condition involving suitable functionals.

Nonlinear systemCompact spaceSettore MAT/05 - Analisi MatematicaDifferential equationGeneral MathematicsMountain pass theoremMathematical analysisMathematics::Analysis of PDEsGeneral Physics and AstronomyHomoclinic orbitLaplace operator(p q)-Laplacian operator Difference equations homoclinic solutions non-zero solutionsMathematicsActa Mathematica Scientia
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Infinitely many solutions for a perturbed nonlinear Navier boundary value problem involving the -biharmonic

2012

By using critical point theory, we establish the existence of infinitely many weak solutions for a class of elliptic Navier boundary value problems depending on two parameters and involving the p-biharmonic operator. © 2012 Elsevier Ltd. All rights reserved.

Nonlinear systemP-biharmonic type operatorsApplied MathematicsMathematical analysisCritical point theoryMathematics::Analysis of PDEsBiharmonic equationInfinitely many solutionNavier boundary value problemBoundary value problemAnalysisCritical point (mathematics)MathematicsNonlinear Analysis: Theory, Methods & Applications
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Two Nontrivial Solutions for Robin Problems Driven by a p–Laplacian Operator

2020

By variational methods and critical point theorems, we show the existence of two nontrivial solutions for a nonlinear elliptic problem under Robin condition and when the nonlinearty satisfies the usual Ambrosetti-Rabinowitz condition.

Nonlinear systemPure mathematicsRobin problemSettore MAT/05 - Analisi Matematicap-LaplacianCritical point theoryMathematics::Analysis of PDEsp-LaplacianRobin problem p-Laplacian Critical point theoryCritical point (mathematics)Mathematics
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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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Removability of a Level Set for Solutions of Quasilinear Equations

2005

In this paper, we study the removability of a level set for the solutions of quasilinear elliptic and parabolic equations of the second order. We show, under rather general assumptions on the coeff...

Partial differential equationDifferential equationIndependent equationApplied MathematicsMathematical analysisMathematics::Analysis of PDEsParabolic partial differential equationEuler equationssymbols.namesakeMethod of characteristicsElliptic partial differential equationsymbolsHyperbolic partial differential equationAnalysisMathematicsCommunications in Partial Differential Equations
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Parabolic equations with natural growth approximated by nonlocal equations

2017

In this paper we study several aspects related with solutions of nonlocal problems whose prototype is $$ u_t =\displaystyle \int_{\mathbb{R}^N} J(x-y) \big( u(y,t) -u(x,t) \big) \mathcal G\big( u(y,t) -u(x,t) \big) dy \qquad \mbox{ in } \, \Omega \times (0,T)\,, $$ being $ u (x,t)=0 \mbox{ in } (\mathbb{R}^N\setminus \Omega )\times (0,T)\,$ and $ u(x,0)=u_0 (x) \mbox{ in } \Omega$. We take, as the most important instance, $\mathcal G (s) \sim 1+ \frac{\mu}{2} \frac{s}{1+\mu^2 s^2 }$ with $\mu\in \mathbb{R}$ as well as $u_0 \in L^1 (\Omega)$, $J$ is a smooth symmetric function with compact support and $\Omega$ is either a bounded smooth subset of $\mathbb{R}^N$, with nonlocal Dirichlet bound…

PhysicsKernel (set theory)Applied MathematicsGeneral Mathematics010102 general mathematicsMathematics::Analysis of PDEs01 natural sciencesParabolic partial differential equationOmega010101 applied mathematicsSymmetric functionCombinatoricssymbols.namesakeMathematics - Analysis of PDEsMathematics - Analysis of PDEs; Mathematics - Analysis of PDEsBounded functionDirichlet boundary conditionsymbolsFOS: MathematicsUniqueness0101 mathematicsAnalysis of PDEs (math.AP)
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Numerical study of a multiscale expansion of the Korteweg de Vries equation and Painlev\'e-II equation

2007

The Cauchy problem for the Korteweg de Vries (KdV) equation with small dispersion of order $\e^2$, $\e\ll 1$, is characterized by the appearance of a zone of rapid modulated oscillations. These oscillations are approximately described by the elliptic solution of KdV where the amplitude, wave-number and frequency are not constant but evolve according to the Whitham equations. Whereas the difference between the KdV and the asymptotic solution decreases as $\epsilon$ in the interior of the Whitham oscillatory zone, it is known to be only of order $\epsilon^{1/3}$ near the leading edge of this zone. To obtain a more accurate description near the leading edge of the oscillatory zone we present a…

PhysicsLeading edgeSmall dispersion limitComputer Science::Information RetrievalGeneral MathematicsMathematical analysisGeneral EngineeringMathematics::Analysis of PDEsGeneral Physics and AstronomyNonlinear equationsDispersive partial differential equationShock wavesAmplitudeNonlinear Sciences::Exactly Solvable and Integrable SystemsInitial value problemWavenumberDispersive shockDispersion (water waves)Constant (mathematics)Korteweg–de Vries equationDevries equationAsymptoticsSettore MAT/07 - Fisica MatematicaNonlinear Sciences::Pattern Formation and SolitonsMathematical Physics
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Some evolution equations arising in physics

1983

In this paper we consider a new series of evolution equations generalizing the Korteweg-deVries (KdV) and Burgers equations, and we report recent advances on these equations together with the physical phenomena where they arise. In particular we consider a generalized Burgers' equation and we sketch a method for solution in series by using the theory of Sobolevskij and Tanabe. Then we study the KdV equation with nonuniformity terms and we describe various physical interpretation of this equation. We consider various particular cases in which varying solitonic solutions exist. Also we sketch a unicity theorem. Finally modified Burgers-KdV equations are considered.

PhysicsNonlinear Sciences::Exactly Solvable and Integrable SystemsSeries (mathematics)Physical phenomenaMathematics::Analysis of PDEsKorteweg–de Vries equationNonlinear Sciences::Pattern Formation and SolitonsSketchMathematical physicsBurgers' equationInterpretation (model theory)
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Polar Sets in a Nonlinear Potential Theory

1988

In this lecture we discuss nonlinear potential theory based on “A-super-harmonic functions”; the theory can be viewed as a (nonlinear) extension of the classical study of superharmonic functions in ℝn.

PhysicsNonlinear systemSubharmonic functionClassical mechanicsMathematics::Analysis of PDEsPolarExtension (predicate logic)Computer Science::DatabasesPotential theory
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High Reynolds number Navier-Stokes solutions and boundary layer separation induced by a rectilinear vortex array

2008

Numerical solutions of Prandtl’s equation and Navier Stokes equations are considered for the two dimensional flow induced by an array of periodic rec- tilinear vortices interacting with an infinite plane. We show how this initial datum develops a separation singularity for Prandtl equation. We investigate the asymptotic validity of boundary layer theory considering numerical solu- tions for the full Navier Stokes equations at high Reynolds numbers.

PhysicsPrandtl numberMathematical analysisMathematics::Analysis of PDEsReynolds numberNon-dimensionalization and scaling of the Navier–Stokes equationsunsteady separationReynolds equationPhysics::Fluid DynamicsFlow separationsymbols.namesakeBoundary layerPrandtl equation interactive viscous–inviscid equation.Navier Stokes solutionsymbolszero viscosity limitNavier–Stokes equationsReynolds-averaged Navier–Stokes equationsSettore MAT/07 - Fisica Matematica
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