Search results for "Operator"

showing 10 items of 1427 documents

Weak Solutions for a (p(z), q(z))-Laplacian Dirichlet Problem

2020

We establish the existence of a nontrivial and nonnegative solution for a double phase Dirichlet problem driven by a (p(z); q(z))-Laplacian operator plus a potential term. Our approach is variational, but the reaction term f need not satisfy the usual in such cases Ambrosetti-Rabinowitz condition.

Dirichlet problemPure mathematicsGeneral MathematicsMathematics::Analysis of PDEsweak solutionLaplace operator(p(z) q(z))-Laplacian operatorMathematics(C-c)-condition
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Two positive solutions for a Dirichlet problem with the (p,q)‐Laplacian

2020

The aim of this paper is to prove the existence of two solutions for a nonlinear elliptic problem involving the (p,q) -Laplacian operator. The solutions are obtained by using variational methods and critical points theorems. The positivity of the solutions is shown by applying a generalized version of the strong maximum principle.

Dirichlet problemPure mathematicsmultiple solutionSettore MAT/05 - Analisi MatematicaGeneral Mathematicscritical pointsemilinear elliptic equationLaplace operator(pq)-LaplacianCritical point (mathematics)Dirichlet problemMathematicsMathematische Nachrichten
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Existence of non-zero solutions for a Dirichlet problem driven by (p(x),q(x)-Laplacian

2021

The paper focuses on a Dirichlet problem driven by the (Formula presented.) -Laplacian. The existence of at least two non-zero solutions under suitable conditions on the nonlinear term is established. The approach is based on variational methods.

Dirichlet problemPure mathematicsmultiple solutionscritical pointsApplied Mathematics010102 general mathematicsZero (complex analysis)q(x))-LaplacianMathematics::Spectral Theory-Laplacian01 natural sciences(p(x)q(x))-Laplacian critical points multiple solutions Dirichlet problemTerm (time)010101 applied mathematicsNonlinear systemSettore MAT/05 - Analisi Matematica0101 mathematics(p(x)Laplace operatorAnalysisDirichlet problemMathematicsApplicable Analysis
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Symmetrization for singular semilinear elliptic equations

2012

In this paper, we prove some comparison results for the solution to a Dirichlet problem associated with a singular elliptic equation and we study how the summability of such a solution varies depending on the summability of the datum f. © 2012 Fondazione Annali di Matematica Pura ed Applicata and Springer-Verlag.

Dirichlet problemSharp a priori estimatesSemilinear elliptic equationsMathematics::Operator AlgebrasApplied MathematicsMathematical analysisMathematics::Classical Analysis and ODEsMathematics::Analysis of PDEsComparison resultsSymmetrizationGeodetic datumElliptic curveSettore MAT/05 - Analisi MatematicaMathematics::K-Theory and HomologySymmetrizationMathematics
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On Noncoercive (p, q)-Equations

2021

We consider a nonlinear Dirichlet problem driven by a (p, q)-Laplace differential operator (1 < q < p). The reaction is (p - 1)-linear near +/-infinity and the problem is noncoercive. Using variational tools and truncation and comparison techniques together with critical groups, we produce five nontrivial smooth solutions all with sign information and ordered. In the particular case when q = 2, we produce a second nodal solution for a total of six nontrivial smooth solutions all with sign information.

Dirichlet problemTruncationGeneral MathematicsMathematical analysisGeneral Physics and AstronomyDifferential operator(pq)-LaplacianNonlinear systemextremal solutionsprincipal eigenvalueSettore MAT/05 - Analisi Matematicanonlinear regularityconstant sign and nodal solutionsSign (mathematics)Mathematics
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Finite element approximations of the wave equation with Dirichlet boundary data defined on a bounded domain in R2

2006

Dirichlet problemsymbols.namesakeDirichlet boundary conditionDirichlet's principleMathematical analysissymbolsMixed finite element methodBoundary value problemDirichlet's energyMixed boundary conditionPoincaré–Steklov operatorMathematics
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Three solutions to mixed boundary value problem driven by p(z)-Laplace operator

2021

We prove the existence of at least three weak solutions to a mixed Dirichlet–Neumann boundary value problem for equations driven by the p(z)-Laplace operator in the principal part. Our approach is variational and use three critical points theorems.

Dirichlet–Neumann boundary value problemSettore MAT/05 - Analisi MatematicaGeneral MathematicsMathematical analysisp(z)-Laplace operatorBoundary value problemvariable exponent Sobolev spaceLaplace operatorMathematics
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Aggregation of Risk Level Assessments Based on Fuzzy Equivalence Relation

2017

The paper deals with the problem of aggregation of risk level assessments. We describe the technique of a risk level evaluation taking into account values of the risk level obtained for objects which are in some sense equivalent. For this purpose we propose to use the construction of a general aggregation operator based on the corresponding fuzzy equivalence relation. Numerical example of the investment risk level aggregation using an equivalence relation obtained on the basis of different macroeconomic factors for countries of one region is considered.

Discrete mathematics0209 industrial biotechnologyMathematical optimizationRisk levelBasis (linear algebra)Financial risk02 engineering and technologyFuzzy equivalence relation020901 industrial engineering & automationOperator (computer programming)0202 electrical engineering electronic engineering information engineeringEquivalence relation020201 artificial intelligence & image processingMathematics
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Fixed Points in Topological *-Algebras of Unbounded Operators

2001

We discuss some results concerning fixed point equations in the setting of topological *-algebras of unbounded operators. In particular, an existence result is obtained for what we have called {\em weak $\tau$ strict contractions}, and some continuity properties of these maps are discussed. We also discuss possible applications of our procedure to quantum mechanical systems.

Discrete mathematics47H10; 46N50Topological algebraGeneral MathematicsMathematics - Operator AlgebrasFOS: Physical sciencesMathematical Physics (math-ph)Fixed pointTopologyFixed-point propertyFixed point equationOperator algebraFOS: Mathematics46N50Operator Algebras (math.OA)Settore MAT/07 - Fisica MatematicaQuantumMathematical Physics47H10operator algebrasMathematics
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The Spectrum of Analytic Mappings of Bounded Type

2000

Abstract A Banach space E is said to be (symmetrically) regular if every continuous (symmetric) linear mapping from E to E ′ is weakly compact. For a complex Banach space E and a complex Banach algebra F , let H b ( E ,  F ) denote the algebra of holomorphic mappings from E to F which are bounded on bounded sets. We endow H b ( E ,  F ) with the usual Frechet topology. M ( H b ( E ,  F ),  F ) denotes the set of all non-null continuous homomorphisms from H b ( E ,  F ) to F . A subset of G EF on which the extension of Zalduendo is multiplicative is presented and it is shown that, in general, the sets G EF and M ( H b ( E ,  F ),  F ) do not coincide. We prove that if E is symmetrically regu…

Discrete mathematicsANÁLISE FUNCIONALhomomorphismApplied MathematicsSpectrum (functional analysis)Multiplicative functionBanach spaceholomorphic mappinganalytic structureBounded typeContinuous linear operatorBounded functionBanach algebraFréchet algebraBanach *-algebraAnalysisMathematicsJournal of Mathematical Analysis and Applications
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