Search results for " Operator"

showing 10 items of 931 documents

Nonlinear vector Duffing inclusions with no growth restriction on the orientor field

2019

We consider nonlinear multivalued Dirichlet Duffing systems. We do not impose any growth condition on the multivalued perturbation. Using tools from the theory of nonlinear operators of monotone type, we prove existence theorems for the convex and the nonconvex problems. Also we show the existence of extremal trajectories and show that such solutions are $C_0^1(T,\mathbb{R}^N)$-dense in the solution set of the convex problem (strong relaxation theorem).

Pure mathematicsApplied MathematicsRegular polygonSolution setPerturbation (astronomy)Dirichlet distributionDuffing systemNonlinear systemsymbols.namesakeMonotone polygonNonlinear operator of mono-tone typeGrowth restrictionSettore MAT/05 - Analisi MatematicaConvex optimizationStrong relaxationssymbolsExtremal solutionAnalysisMathematics
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Weak solution for Neumann (p,q)-Laplacian problem on Riemannian manifold

2019

We prove the existence of a nontrivial solution for a nonlinear (p, q)-Laplacian problem with Neumann boundary condition, on a non compact Riemannian manifold. The idea is to reduce the problem in variational form, which means to consider the critical points of the corresponding Euler-Lagrange functional in an Orlicz-Sobolev space. (C) 2019 Elsevier Inc. All rights reserved.

Pure mathematicsApplied MathematicsWeak solution010102 general mathematicsRiemannian manifoldSpace (mathematics)01 natural sciences010101 applied mathematicsNonlinear systemSettore MAT/05 - Analisi MatematicaNeumann boundary condition(p q)-Laplacian operator Riemannian manifold Weak solution0101 mathematicsLaplace operatorAnalysisMathematics
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HOLOMORPHIC SUPERPOSITION OPERATORS BETWEEN BANACH FUNCTION SPACES

2013

AbstractWe prove that for a large class of Banach function spaces continuity and holomorphy of superposition operators are equivalent and that bounded superposition operators are continuous. We also use techniques from infinite dimensional holomorphy to establish the boundedness of certain superposition operators. Finally, we apply our results to the study of superposition operators on weighted spaces of holomorphic functions and the$F(p, \alpha , \beta )$spaces of Zhao. Some independent properties on these spaces are also obtained.

Pure mathematicsApproximation propertyGeneral MathematicsHolomorphic functional calculusBanach manifoldFinite-rank operatorInfinite-dimensional holomorphyOperator theoryIdentity theoremLp spaceMathematicsJournal of the Australian Mathematical Society
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Intrinsic characterizations of perturbation classes on some Banach spaces

2010

We investigate relationships between inessential operators and improjective operators acting between Banach spaces X and Y, emphasizing the case in which one of the spaces is a C(K) space. We show that they coincide in many cases, but they are different in the case X=Y =C(K 0), where K 0 is a compact space constructed by Koszmider. Mathematics Subject Classification (2000)47A53 KeywordsInessential operators-Improjective operators-Fredholm theory

Pure mathematicsApproximation propertyNuclear operatorGeneral MathematicsMathematical analysisInterpolation spaceBirnbaum–Orlicz spaceFinite-rank operatorBanach manifoldLp spaceInessential operators improjective operatorsCompact operator on Hilbert spaceMathematics
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Strong Converse Results for Linking Operators and Convex Functions

2020

We consider a family B n , ρ c of operators which is a link between classical Baskakov operators (for ρ = ∞ ) and their genuine Durrmeyer type modification (for ρ = 1 ). First, we prove that for fixed n , c and a fixed convex function f , B n , ρ c f is decreasing with respect to ρ . We give two proofs, using various probabilistic considerations. Then, we combine this property with some existing direct and strong converse results for classical operators, in order to get such results for the operators B n , ρ c applied to convex functions.

Pure mathematicsArticle Subject010102 general mathematicsMathematicsofComputing_GENERALProbabilistic logicType (model theory)Mathematical proof01 natural sciences010104 statistics & probabilityTheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGESBaskakov operatorConverseQA1-939Order (group theory)0101 mathematicsConvex functionLink (knot theory)AnalysisMathematicsMathematicsJournal of Function Spaces
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Malliavin Calculus of Bismut Type for Fractional Powers of Laplacians in Semi-Group Theory

2011

We translate into the language of semi-group theory Bismut's Calculus on boundary processes (Bismut (1983), Lèandre (1989)) which gives regularity result on the heat kernel associated with fractional powers of degenerated Laplacian. We translate into the language of semi-group theory the marriage of Bismut (1983) between the Malliavin Calculus of Bismut type on the underlying diffusion process and the Malliavin Calculus of Bismut type on the subordinator which is a jump process.

Pure mathematicsArticle SubjectSubordinatorlcsh:MathematicsApplied MathematicsBoundary (topology)Type (model theory)lcsh:QA1-939Malliavin calculusMathematics::ProbabilityMathematics::K-Theory and HomologyCalculusMathematics::Differential GeometryLaplace operatorJump processAnalysisHeat kernelGroup theoryMathematicsInternational Journal of Differential Equations
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Hamiltonians Generated by Parseval Frames

2021

AbstractIt is known that self-adjoint Hamiltonians with purely discrete eigenvalues can be written as (infinite) linear combination of mutually orthogonal projectors with eigenvalues as coefficients of the expansion. The projectors are defined by the eigenvectors of the Hamiltonians. In some recent papers, this expansion has been extended to the case in which these eigenvectors form a Riesz basis or, more recently, a ${\mathcal{D}}$ D -quasi basis (Bagarello and Bellomonte in J. Phys. A 50:145203, 2017, Bagarello et al. in J. Math. Phys. 59:033506, 2018), rather than an orthonormal basis. Here we discuss what can be done when these sets are replaced by Parseval frames. This interest is moti…

Pure mathematicsBasis (linear algebra)Applied MathematicsFrames Hamiltonian operators Orthonormal basesSpectrum (functional analysis)Hilbert spacePhysical systemObservableComputer Science::Digital LibrariesParseval's theoremsymbols.namesakeComputer Science::Mathematical SoftwaresymbolsOrthonormal basisSettore MAT/07 - Fisica MatematicaEigenvalues and eigenvectorsMathematics
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Approximation properties of λ-Kantorovich operators

2018

In the present paper, we study a new type of Bernstein operators depending on the parameter \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\lambda\in[-1,1]$\end{document}λ∈[−1,1]. The Kantorovich modification of these sequences of linear positive operators will be considered. A quantitative Voronovskaja type theorem by means of Ditzian–Totik modulus of smoothness is proved. Also, a Grüss–Voronovskaja type theorem for λ-Kantorovich operators is provided. Some numerical examples which show the relevance of the res…

Pure mathematicsBernstein operatorModulus of smoothnessResearchApplied Mathematicslcsh:Mathematics010102 general mathematicsType (model theory)Rate of convergenceLambdalcsh:QA1-93901 natural sciences010101 applied mathematicsRate of convergenceVoronovskaja theorem41A10Discrete Mathematics and CombinatoricsKantorovich operators0101 mathematics41A2541A36AnalysisMathematicsJournal of Inequalities and Applications
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Multiple Solutions with Sign Information for a Class of Coercive (p, 2)-Equations

2019

We consider a nonlinear Dirichlet equation driven by the sum of a p-Laplacian and of a Laplacian (a (p, 2)-equation). The hypotheses on the reaction f(z, x) are minimal and make the energy (Euler) functional of the problem coercive. We prove two multiplicity theorems producing three and four nontrivial smooth solutions, respectively, all with sign information. We apply our multiplicity results to the particular case of a class of parametric (p, 2)-equations.

Pure mathematicsClass (set theory)Constant sign solutionGeneral MathematicsNodal solutions010102 general mathematicsMultiplicity (mathematics)01 natural sciencesDirichlet distribution010101 applied mathematicssymbols.namesakeNonlinear systemSettore MAT/05 - Analisi MatematicaEuler's formulasymbolsHomotopy0101 mathematicsLaplace operator(p 2)-differential operatorCritical groupSign (mathematics)Parametric statisticsMathematicsBulletin of the Malaysian Mathematical Sciences Society
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Quasi *-algebras of measurable operators

2009

Non-commutative $L^p$-spaces are shown to constitute examples of a class of Banach quasi *-algebras called CQ*-algebras. For $p\geq 2$ they are also proved to possess a {\em sufficient} family of bounded positive sesquilinear forms satisfying certain invariance properties. CQ *-algebras of measurable operators over a finite von Neumann algebra are also constructed and it is proven that any abstract CQ*-algebra $(\X,\Ao)$ possessing a sufficient family of bounded positive tracial sesquilinear forms can be represented as a CQ*-algebra of this type.

Pure mathematicsClass (set theory)Mathematics::Operator AlgebrasGeneral MathematicsNon-commutative integrationPartial algebras of operatorsFOS: Physical sciencesMathematical Physics (math-ph)Type (model theory)symbols.namesakeVon Neumann algebraSettore MAT/05 - Analisi MatematicaBounded functionsymbolsBanach C*-moduleSettore MAT/07 - Fisica MatematicaMathematical PhysicsMathematics
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