Search results for "Applied Mathematics"

showing 10 items of 4379 documents

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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Existence and comparison results for a singular semilinear elliptic equation with a lower order term

2014

This paper deals with the homogeneous Dirichlet problem for a singular semilinear elliptic equation with a first order term. When the datum is bounded we prove an existence result and we show that any solution can be compared with the solution to a suitable symmetrized problem.

Dirichlet problemSharp a priori estimatesSingular elliptic problems with gradient termApplied MathematicsGeneral MathematicsNumerical analysisMathematical analysisMathematics::Analysis of PDEsGeodetic datumSymmetrizationTerm (time)Elliptic curveSingular solutionSettore MAT/05 - Analisi MatematicaBounded functionSymmetrizationMathematics
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Multiple solutions for parametric double phase Dirichlet problems

2020

We consider a parametric double phase Dirichlet problem. Using variational tools together with suitable truncation and comparison techniques, we show that for all parametric values [Formula: see text] the problem has at least three nontrivial solutions, two of which have constant sign. Also, we identify the critical parameter [Formula: see text] precisely in terms of the spectrum of the [Formula: see text]-Laplacian.

Dirichlet problemlocal minimizersTruncationApplied MathematicsGeneral MathematicsMusielak-Orlicz-Sobolev spacesDirichlet distributionsymbols.namesakeDouble phaseSettore MAT/05 - Analisi MatematicaDouble phase integrandsymbolseigenvalues of the q-LaplacianApplied mathematicsSettore MAT/03 - Geometriaunbalanced growthParametric statisticsMathematics
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On Uncertain Discontinuous Functions and Quasi-equilibrium in Some Economic Models

2020

In the paper is studied some properties of uncertain discontinuous mappings, the so-called w-discontinuous mappings. Based on them, the existence of a quasi-equilibrium for a new economic model is proved.

Discontinuity (linguistics)Fixed-point theoremApplied mathematicsEconomic modelQuasistatic processMathematics
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On the Ball-Marsden-Slemrod obstruction for bilinear control systems

2019

International audience; In this paper we present an extension to the case of $L^1$-controls of a famous result by Ball--Marsden--Slemrod on the obstruction to the controllability of bilinear control systems in infinite dimensional spaces.

Discrete mathematics010102 general mathematics01 natural sciences010101 applied mathematicsControllabilityAlgebraBilinear controlOptimization and Control (math.OC)Settore MAT/05FOS: MathematicsBall (mathematics)[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC]0101 mathematicsMathematics - Optimization and ControlMathematics::Symplectic GeometryMathematics
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On Strong Convergence of Halpern’s Method for Quasi-Nonexpansive Mappings in Hilbert Spaces

2016

In this paper, we introduce a Halpern’s type method to approximate common fixed points of a nonexpansive mapping T and a strongly quasi-nonexpansive mappings S, defined in a Hilbert space, such that I − S is demiclosed at 0. The result shows as the same algorithm converges to different points, depending on the assumptions of the coefficients. Moreover, a numerical example of our iterative scheme is given.

Discrete mathematics010102 general mathematicsHilbert spaceApproximation algorithmFixed pointType (model theory)variational inequality01 natural sciences010101 applied mathematicssymbols.namesakefixed pointModeling and SimulationScheme (mathematics)Variational inequalityConvergence (routing)symbolsQA1-9390101 mathematicsAnalysisapproximation algorithmMathematicsMathematicsMathematical Modelling and Analysis
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Information potential for some probability density functions

2021

Abstract This paper is related to the information theoretic learning methodology, whose goal is to quantify global scalar descriptors (e.g., entropy) of a given probability density function (PDF). In this context, the core concept is the information potential (IP) S [ s ] ( x ) : = ∫ R p s ( t , x ) d t , s > 0 of a PDF p(t, x) depending on a parameter x; it is naturally related to the Renyi and Tsallis entropies. We present several such PDF, viewed also as kernels of integral operators, for which a precise relation exists between S[2](x) and the variance Var[p(t, x)]. For these PDF we determine explicitly the IP and the Shannon entropy. As an application to Information Theoretic Learning w…

Discrete mathematics0209 industrial biotechnologyApplied MathematicsComputation020206 networking & telecommunicationsProbability density function02 engineering and technologyExpected valueStatistical powerConvexityComputational Mathematics020901 industrial engineering & automation0202 electrical engineering electronic engineering information engineeringKurtosisEntropy (information theory)MathematicsApplied Mathematics and Computation
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From fuzzy metric spaces to modular metric spaces: a fixed point approach

2017

We propose an intuitive theorem which uses some concepts of auxiliary functions for establishing existence and uniqueness of the fixed point of a self-mapping. First we work in the setting of fuzzy metric spaces in the sense of George and Veeramani, then we deduce some consequences in modular metric spaces. Finally, a sample homotopy result is derived making use of the main theorem.

Discrete mathematics021103 operations researchAlgebra and Number TheoryInjective metric space0211 other engineering and technologiesT-norm02 engineering and technologyEquivalence of metrics01 natural sciencesIntrinsic metricConvex metric space010101 applied mathematicsMetric spaceFixed point fuzzy metric space modular metric spaceSettore MAT/05 - Analisi MatematicaMetric (mathematics)Metric mapSettore MAT/03 - Geometria0101 mathematicsAnalysisMathematicsThe Journal of Nonlinear Sciences and Applications
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Thin and fat sets for doubling measures in metric spaces

2011

We consider sets in uniformly perfect metric spaces which are null for every doubling measure of the space or which have positive measure for all doubling measures. These sets are called thin and fat, respectively. In our main results, we give sufficient conditions for certain cut-out sets being thin or fat.

Discrete mathematics28A12 (Primary) 30L10 (Secondary)General MathematicsInjective metric space010102 general mathematicsNull (mathematics)Space (mathematics)01 natural sciencesMeasure (mathematics)Thin setIntrinsic metric010101 applied mathematicsMetric spaceMathematics - Classical Analysis and ODEsMetric (mathematics)Classical Analysis and ODEs (math.CA)FOS: Mathematics0101 mathematicsMathematics
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A function whose graph has positive doubling measure

2014

We show that a doubling measure on the plane can give positive measure to the graph of a continuous function. This answers a question by Wang, Wen and Wen. Moreover we show that the doubling constant of the measure can be chosen to be arbitrarily close to the doubling constant of the Lebesgue measure.

Discrete mathematics28A12 (Primary) 30L10 (Secondary)Lebesgue measureApplied MathematicsGeneral Mathematicsta111thin setThin setMathematics - Classical Analysis and ODEsfat setdoubling measureClassical Analysis and ODEs (math.CA)FOS: MathematicsGraph (abstract data type)Computer Science::DatabasesMathematicsProceedings of the American Mathematical Society
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