Search results for "regularity"

showing 10 items of 98 documents

A Lebesgue-type decomposition for non-positive sesquilinear forms

2018

A Lebesgue-type decomposition of a (non necessarily non-negative) sesquilinear form with respect to a non-negative one is studied. This decomposition consists of a sum of three parts: two are dominated by an absolutely continuous form and a singular non-negative one, respectively, and the latter is majorized by the product of an absolutely continuous and a singular non-negative forms. The Lebesgue decomposition of a complex measure is given as application.

Complex measurePure mathematicsSesquilinear formType (model theory)Lebesgue integration01 natural sciencesRegularitysymbols.namesakeSettore MAT/05 - Analisi MatematicaLebesgue decomposition0103 physical sciencesDecomposition (computer science)Complex measureFOS: Mathematics0101 mathematicsMathematicsMathematics::Functional AnalysisSingularitySesquilinear formApplied Mathematics010102 general mathematicsAbsolute continuityFunctional Analysis (math.FA)Mathematics - Functional Analysis47A07 15A63 28A12 47A12Product (mathematics)symbols010307 mathematical physicsNumerical range
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Harmony perception and regularity of spike trains in a simple auditory model

2013

A probabilistic approach for investigating the phenomena of dissonance and consonance in a simple auditory sensory model, composed by two sensory neurons and one interneuron, is presented. We calculated the interneuron’s firing statistics, that is the interspike interval statistics of the spike train at the output of the interneuron, for consonant and dissonant inputs in the presence of additional "noise", representing random signals from other, nearby neurons and from the environment. We find that blurry interspike interval distributions (ISIDs) characterize dissonant accords, while quite regular ISIDs characterize consonant accords. The informational entropy of the non-Markov spike train …

ConsonantInterneuronSpeech recognitionSpike trainmedia_common.quotation_subjectSensory systemConsonance and dissonanceSound perceptionSettore FIS/03 - Fisica Della Materiamedicine.anatomical_structureAuditory system consonant and dissonant accords environmental noise hidden Markov chain informational entropy regularityPerceptionmedicineAuditory systemMathematicsmedia_commonAIP Conference Proceedings
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Singular Double Phase Problems with Convection

2020

We consider a nonlinear Dirichlet problem driven by the sum of a $p$ -Laplacian and of a $q$ -Laplacian (double phase equation). In the reaction we have the combined effects of a singular term and of a gradient dependent term (convection) which is locally defined. Using a mixture of variational and topological methods, together with suitable truncation and comparison techniques, we prove the existence of a positive smooth solution.

ConvectionDirichlet problemPartial differential equationTruncationApplied Mathematics010102 general mathematicsMathematical analysisSingular termFixed pointMathematics::Spectral Theory01 natural sciencesTerm (time)Positive solution010101 applied mathematicsNonlinear system(p q)-LaplacianSettore MAT/05 - Analisi MatematicaNonlinear maximum principle0101 mathematicsLaplace operatorNonlinear regularityMathematicsActa Applicandae Mathematicae
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Positive solutions for nonlinear Robin problems with convection

2019

We consider a nonlinear Robin problem driven by the p-Laplacian and with a convection term f(z,x,y). Without imposing any global growth condition on f(z,·,·) and using topological methods (the Leray-Schauder alternative principle), we show the existence of a positive smooth solution.

ConvectionGeneral Mathematicsnonlinear maximum principlep-LaplacianGeneral Engineering(minimal) positive solutionNonlinear systemEngineering (all)p-LaplacianApplied mathematicsnonlinear regularityMathematics (all)convection termLeray-Schauder alternative principleMathematics
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Estudio climático del exponente “n” de las curvas IDF: aplicación para la Península Ibérica

2009

El análisis de las precipitaciones máximas suele llevarse a cabo mediante curvas IDF (Intensidad-Duración-Frecuencia), que a su vez pueden expresarse como curvas IMM (Intensidades Medias Máximas). En este trabajo, hemos desarrollado un índice “n”, definido a partir del exponente que se obtiene de ajustar las curvas climáticas IDF a las curvas IMM. Dicho índice proporciona información sobre el modo en que se alcanzan las precipitaciones máximas en una determinada zona clim´atica, atendiendo a la distribuci´on temporal relativa de las intensidades m´aximas. A partir del an´alisis clim´atico del ´ındice “n”, en la Pen´ınsula Ib´erica se pueden distinguir grandes zonas caracterizadas por m´axim…

Curvas IMMUNESCO::CIENCIAS DE LA TIERRA Y DEL ESPACIO::ClimatologíaRegularity indexCurvas IDF:CIENCIAS DE LA TIERRA Y DEL ESPACIO::Climatología [UNESCO]Intensidad precipitaciónIDF curvesPrecipitation intensityÍndice regularidadMAI curves
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Limits of Sobolev homeomorphisms

2017

Let X; Y subset of R-2 be topologically equivalent bounded Lipschitz domains. We prove that weak and strong limits of homeomorphisms h: X (onto)-> Y in the Sobolev space W-1,W-p (X, R-2), p >= 2; are the same. As an application, we establish the existence of 2D-traction free minimal deformations for fairly general energy integrals. Peer reviewed

DIRICHLET ENERGYGeneral MathematicsDEFORMATIONSMONOTONE MAPPINGSLAPLACE EQUATION01 natural sciencesvariational integralsSobolev inequalityp-harmonic equationNONLINEAR ELASTICITYharmonic mappings111 MathematicsPOINTWISE HARDY INEQUALITIESREGULARITYSPACE0101 mathematicsMathematicsDISTORTIONSURFACESApplied Mathematics010102 general mathematicsMathematical analysisEnergy-minimal deformationsDirichlet's energy010101 applied mathematicsSobolev spaceapproximation of Sobolev homeomorphismsNonlinear elasticityJournal of the European Mathematical Society
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Maximal ℓ p ‐regularity of multiterm fractional equations with delay

2020

[EN] We provide a characterization for the existence and uniqueness of solutions in the space of vector-valued sequences l(p) (Z, X)for the multiterm fractional delayed model in the form Delta(alpha)u(n) + lambda Delta(beta)u(n) = Lambda u(n) + u(n-tau) + f(n), n is an element of Z, alpha, beta is an element of R+, tau is an element of Z, lambda is an element of R, where X is a Banach space, A is a closed linear operator with domain D(A) defined on X, f is an element of l(p)(Z,X) and Delta(Gamma) denotes the Grunwald-Letkinov fractional derivative of order Gamma > 0. We also give some conditions to ensure the existence of solutions when adding nonlinearities. Finally, we illustrate our resu…

DelayMaximal l(p)-regularityMultiterm fractionalGeneral MathematicsFractional equationsGeneral EngineeringApplied mathematicsGrunwald-Letnikov derivativeMATEMATICA APLICADAGrünwald–Letnikov derivativeMathematicsMathematical Methods in the Applied Sciences
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(p, 2)-Equations with a Crossing Nonlinearity and Concave Terms

2018

We consider a parametric Dirichlet problem driven by the sum of a p-Laplacian ($$p>2$$) and a Laplacian (a (p, 2)-equation). The reaction consists of an asymmetric $$(p-1)$$-linear term which is resonant as $$x \rightarrow - \infty $$, plus a concave term. However, in this case the concave term enters with a negative sign. Using variational tools together with suitable truncation techniques and Morse theory (critical groups), we show that when the parameter is small the problem has at least three nontrivial smooth solutions.

Dirichlet problem0209 industrial biotechnologyControl and OptimizationMultiple smooth solutionTruncationConcave termApplied Mathematicsp-Laplacian010102 general mathematicsMathematical analysis02 engineering and technology01 natural sciencesTerm (time)Nonlinear system020901 industrial engineering & automationSettore MAT/05 - Analisi MatematicaCrossing nonlinearityNonlinear maximum principle0101 mathematicsLaplace operatorCritical groupNonlinear regularityMorse theoryParametric statisticsMathematicsApplied Mathematics & Optimization
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Positive solutions for singular (p, 2)-equations

2019

We consider a nonlinear nonparametric Dirichlet problem driven by the sum of a p-Laplacian and of a Laplacian (a (p, 2)-equation) and a reaction which involves a singular term and a $$(p-1)$$ -superlinear perturbation. Using variational tools and suitable truncation and comparison techniques, we show that the problem has two positive smooth solutions.

Dirichlet problemApplied MathematicsGeneral Mathematics010102 general mathematicsNonparametric statisticsSingular termGeneral Physics and AstronomyPerturbation (astronomy)Mathematics::Spectral Theory01 natural sciences010101 applied mathematicsNonlinear systemSettore MAT/05 - Analisi MatematicaSingular term Superlinear perturbation Positive solution Nonlinear regularity Truncation Maximum principle Double phase problemApplied mathematics0101 mathematicsLaplace operatorMathematicsZeitschrift für angewandte Mathematik und Physik
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Regularity of renormalized solutions to nonlinear elliptic equations away from the support of measure data

2018

We prove boundedness and continuity for solutions to the Dirichlet problem for the equation $$ - {\rm{div}}(a(x,\nabla u)) = h(x,u) + \mu ,\;\;\;\;\;{\rm{in}}\;{\rm{\Omega }} \subset \mathbb{R}^{N},$$ where the left-hand side is a Leray-Lions operator from $$- {W}^{1,p}_0(\Omega)$$ into W−1,p′(Ω) with 1 < p < N, h(x,s) is a Caratheodory function which grows like ∣s∣p−1 and μ is a finite Radon measure. We prove that renormalized solutions, though not globally bounded, are Holder-continuous far from the support of μ.

Dirichlet problemElliptic partial differential equations; boundary-value problems; regularity; Hölder-continuityregularityOperator (physics)boundary-value problemsElliptic partial differential equationsHölder-continuityMeasure (mathematics)OmegaCombinatoricsBounded functionRadon measurep-LaplacianNabla symbolMathematics
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