Search results for "Differential operator"

showing 10 items of 70 documents

Analytic Bergman operators in the semiclassical limit

2018

Transposing the Berezin quantization into the setting of analytic microlocal analysis, we construct approximate semiclassical Bergman projections on weighted $L^2$ spaces with analytic weights, and show that their kernel functions admit an asymptotic expansion in the class of analytic symbols. As a corollary, we obtain new estimates for asymptotic expansions of the Bergman kernel on $\mathbb{C}^n$ and for high powers of ample holomorphic line bundles over compact complex manifolds.

Pure mathematicsadjoint operatorsMicrolocal analysis32A2501 natural sciences[MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph]Limit (mathematics)Bergman projectionComplex Variables (math.CV)[MATH]Mathematics [math]Mathematics::Symplectic GeometryMathematical PhysicsBergman kernelMathematicsasymptotic expansionweighted L2-estimates58J40[MATH.MATH-CV]Mathematics [math]/Complex Variables [math.CV]Mathematical Physics (math-ph)16. Peace & justiceFunctional Analysis (math.FA)Mathematics - Functional Analysisasymptoticstheoremkernelanalytic pseudodifferential operator010307 mathematical physicsAsymptotic expansion47B35classical limitAnalysis of PDEs (math.AP)Toeplitz operatorGeneral Mathematics70H15Holomorphic functionFOS: Physical sciencesSemiclassical physicsKähler manifold[MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA]analytic symbolsMathematics - Analysis of PDEskahler-metrics0103 physical sciencesFOS: Mathematics[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]0101 mathematicsMathematics - Complex VariablesMathematics::Complex Variables010102 general mathematics32W25space35A27Kähler manifoldmicrolocal analysisToeplitz operatorquantizationsemiclassical analysis
researchProduct

Solutions and positive solutions for superlinear Robin problems

2019

We consider nonlinear, nonhomogeneous Robin problems with a (p − 1)-superlinear reaction term, which need not satisfy the Ambrosetti-Rabinowitz condition. We look for positive solutions and prove existence and multiplicity theorems. For the particular case of the p-Laplacian, we prove existence results under a different geometry near the origin.We consider nonlinear, nonhomogeneous Robin problems with a (p − 1)-superlinear reaction term, which need not satisfy the Ambrosetti-Rabinowitz condition. We look for positive solutions and prove existence and multiplicity theorems. For the particular case of the p-Laplacian, we prove existence results under a different geometry near the origin.

Pure mathematicsnonlinear maximum principle010102 general mathematicsMathematics::Analysis of PDEssuperlinear reactionStatistical and Nonlinear PhysicsMultiplicity (mathematics)01 natural sciencesTerm (time)Nonlinear systempositive solutionSettore MAT/05 - Analisi Matematica0103 physical sciencesNonhomogeneous differential operatornonlinear regularity010307 mathematical physics0101 mathematicscritical groupsMathematical PhysicsMathematicsJournal of Mathematical Physics
researchProduct

Rational Solutions to the KdV Equation in Terms of Particular Polynomials

2022

Here, we construct rational solutions to the KdV equation by particular polynomials. We get the solutions in terms of determinants of the order n for any positive integer n, and we call these solutions, solutions of the order n. Therefore, we obtain a very efficient method to get rational solutions to the KdV equation, and we can construct explicit solutions very easily. In the following, we present some solutions until order 10.

Rational solution[MATH] Mathematics [math]PolynomialBilinear differential operator
researchProduct

Nonlinear multivalued Duffing systems

2018

We consider a multivalued nonlinear Duffing system driven by a nonlinear nonhomogeneous differential operator. We prove existence theorems for both the convex and nonconvex problems (according to whether the multivalued perturbation is convex valued or not). Also, we show that the solutions of the nonconvex problem are dense in those of the convex (relaxation theorem). Our work extends the recent one by Kalita-Kowalski (JMAA, https://doi.org/10.1016/j.jmaa. 2018.01.067).

RelaxationMathematics::General TopologyPerturbation (astronomy)34A60 34B1501 natural sciencesMathematics - Analysis of PDEsContinuous and measurable selectionNonlinear differential operatorSettore MAT/05 - Analisi MatematicaClassical Analysis and ODEs (math.CA)FOS: Mathematics0101 mathematicsMathematicsApplied Mathematics010102 general mathematicsMathematical analysisRegular polygonFixed pointDifferential operatorDuffing system010101 applied mathematicsNonlinear systemMathematics - Classical Analysis and ODEsAnalysisConvex and nonconvex problemAnalysis of PDEs (math.AP)Journal of Mathematical Analysis and Applications
researchProduct

Existence and Relaxation Results for Second Order Multivalued Systems

2021

AbstractWe consider nonlinear systems driven by a general nonhomogeneous differential operator with various types of boundary conditions and with a reaction in which we have the combined effects of a maximal monotone term $A(x)$ A ( x ) and of a multivalued perturbation $F(t,x,y)$ F ( t , x , y ) which can be convex or nonconvex valued. We consider the cases where $D(A)\neq \mathbb{R}^{N}$ D ( A ) ≠ R N and $D(A)= \mathbb{R}^{N}$ D ( A ) = R N and prove existence and relaxation theorems. Applications to differential variational inequalities and control systems are discussed.

RelaxationPure mathematicsPartial differential equationApplied Mathematics010102 general mathematicsMaximal monotone mapOrder (ring theory)Differential operator01 natural sciencesOptimal control010101 applied mathematicsNonlinear systemMonotone polygonSettore MAT/05 - Analisi MatematicaContinuous and measurable selectionsVariational inequalityConvex and nonconvex problemsRelaxation (physics)Boundary value problem0101 mathematicsMathematicsActa Applicandae Mathematicae
researchProduct

Distribution of Eigenvalues for Semi-classical Elliptic Operators with Small Random Perturbations, Results and Outline

2019

In this chapter we will state a result asserting that for elliptic semi-classical (pseudo-)differential operators the eigenvalues are distributed according to Weyl’s law “most of the time” in a probabilistic sense. The first three sections are devoted to the formulation of the results and in the last section we give an outline of the proof that will be carried out in Chaps. 16 and 17.

Section (fiber bundle)Pure mathematicsElliptic operatorDistribution (number theory)Probabilistic logicState (functional analysis)Differential operatorEigenvalues and eigenvectorsMathematics
researchProduct

On essential maximality of linear pseudo-differential operators

1989

Semi-elliptic operatorAlgebraGeneral MathematicsMathematical analysisFinite-rank operatorOperator theoryDifferential operatorOperator normFourier integral operatorQuasinormal operatorMathematics
researchProduct

Sur une classe d’equations du type parabolique lineaires

1996

The application of the variational method for the existence theorem, developped by J. L. Lions, for the evolution equations in Hilbert spaces to a considerably large class of systems of linear partial differential equations of parabolic type is studied by defining Hilbert spaces in relation to the elliptic operator of the system, and an example insired by the system of equations for a viscous gas is examined.

Semi-elliptic operatorElliptic operatorsymbols.namesakeElliptic partial differential equationGeneral MathematicsMathematical analysisHilbert spacesymbolsHilbert's nineteenth problemC0-semigroupSymbol of a differential operatorNumerical partial differential equationsMathematicsRendiconti del Circolo Matematico di Palermo
researchProduct

Positive and nodal solutions for nonlinear nonhomogeneous parametric neumann problems

2020

We consider a parametric Neumann problem driven by a nonlinear nonhomogeneous differential operator plus an indefinite potential term. The reaction term is superlinear but does not satisfy the Ambrosetti-Rabinowitz condition. First we prove a bifurcation-type result describing in a precise way the dependence of the set of positive solutions on the parameter λ > 0. We also show the existence of a smallest positive solution. Similar results hold for the negative solutions and in this case we have a biggest negative solution. Finally using the extremal constant sign solutions we produce a smooth nodal solution.

Settore MAT/05 - Analisi MatematicaNonlinear maximum principleStrong comparisonNodal solutionNonlinear nonhomogeneous differential operatorBifurcation-type theoremCritical groupNonlinear regularity theory
researchProduct

Boundedness and spectral invariance for standard pseudodifferential operators on anisotropically weighted LP-Sobolev spaces

1990

It is shown that pseudodifferential operators with symbols in the standard classes S ρ,δ m (ℝn) define bounded maps between large classes of weighted LP-Sobolev spaces where the growth of the weight does not have to be isotropic. Moreover, the spectrum is independent of the choice of the space.

Sobolev spaceAlgebra and Number TheoryPseudodifferential operatorsBounded functionMathematical analysisSpectrum (functional analysis)IsotropySpace (mathematics)AnalysisMathematicsIntegral Equations and Operator Theory
researchProduct