Search results for " Regular"

showing 10 items of 197 documents

The one loop gluon emission light cone wave function

2017

Light cone perturbation theory has become an essential tool to calculate cross sections for various small-$x$ dilute-dense processes such as deep inelastic scattering and forward proton-proton and proton-nucleus collisions. Here we set out to do one loop calculations in an explicit helicity basis in the four dimensional helicity scheme. As a first process we calculate light cone wave function for one gluon emission to one-loop order in Hamiltonian perturbation theory on the light front. We regulate ultraviolet divergences with transverse dimensional regularization and soft divergences with using a cut-off on longitudinal momentum. We show that when all the renormalization constants are comb…

COLLISIONSParticle physicsNuclear TheoryRENORMALIZATIONQUANTUM ELECTRODYNAMICSGeneral Physics and AstronomyFOS: Physical sciencesloop calculations114 Physical sciences01 natural scienceslight cone perturbation theoryRenormalizationNuclear Theory (nucl-th)Dimensional regularizationHigh Energy Physics - Phenomenology (hep-ph)INFINITE-MOMENTUMLight cone0103 physical sciencesSCATTERINGHelicity basis010306 general physicsNuclear ExperimentQuantum chromodynamicsPhysicsCoupling constantgluon emissionta114010308 nuclear & particles physicsCOLOR GLASS CONDENSATEDeep inelastic scatteringFRONT QCDHelicityEVOLUTIONHigh Energy Physics - PhenomenologyCHROMODYNAMICSQuantum electrodynamicsgluon saturation
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Existence and Regularity for a Class of Nonlinear Hyperbolic Boundary Value Problems

2002

AbstractThe regularity of the solution of the telegraph system with nonlinear monotone boundary conditions is investigated by two methods. The first one is based on D'Alembert-type representation formulae for the solution. In the second method the telegraph system is reduced to a linear Cauchy problem with a locally Lipschitzian functional perturbation; then regularity results are established by appealing to the theory of linear semigroups.

Cauchy problemtelegraph systemApplied MathematicsMathematical analysisD'Alembert formulaeMixed boundary conditionRobin boundary conditionNonlinear systemhigher regularitynonlinear boundary conditionsFree boundary problemNeumann boundary conditionsemigroup approachApplied mathematicsCauchy boundary conditionBoundary value problemAnalysisMathematicsJournal of Mathematical Analysis and Applications
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A two-phase problem with Robin conditions on the free boundary

2020

We study for the first time a two-phase free boundary problem in which the solution satisfies a Robin boundary condition. We consider the case in which the solution is continuous across the free boundary and we prove an existence and a regularity result for minimizers of the associated variational problem. Finally, in the appendix, we give an example of a class of Steiner symmetric minimizers. peerReviewed

Class (set theory)General MathematicsBoundary (topology)variaatiolaskentaRobin boundary conditionsPhase problemRobin boundary condition01 natural sciencesFree boundary problemsRegularityMathematics - Analysis of PDEsFOS: MathematicsFree boundary problemApplied mathematics0101 mathematicsMathematicsosittaisdifferentiaaliyhtälöt010102 general mathematicsFree boundary problemFree boundary problems; Regularity; Robin boundary conditions; Two-phasematemaattinen optimointi16. Peace & justiceRobin boundary condition010101 applied mathematicsTwo-phaseAnalysis of PDEs (math.AP)
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Nonlinear Nonhomogeneous Robin Problems with Almost Critical and Partially Concave Reaction

2020

We consider a nonlinear Robin problem driven by a nonhomogeneous differential operator, with reaction which exhibits the competition of two Caratheodory terms. One is parametric, $$(p-1)$$-sublinear with a partially concave nonlinearity near zero. The other is $$(p-1)$$-superlinear and has almost critical growth. Exploiting the special geometry of the problem, we prove a bifurcation-type result, describing the changes in the set of positive solutions as the parameter $$\lambda >0$$ varies.

Competition phenomenacompetition phenomenanonlinear maximum principleAlmost critical growthLambda01 natural sciencesSet (abstract data type)symbols.namesakeMathematics - Analysis of PDEsSettore MAT/05 - Analisi Matematica0103 physical sciencesFOS: Mathematics0101 mathematicsbifurcation-type resultMathematicsParametric statisticsNonlinear regularity35J20 35J60010102 general mathematicsMathematical analysisZero (complex analysis)udc:517.956.2Differential operatorBifurcation-type resultalmost critical growthNonlinear systemDifferential geometryFourier analysissymbolsnonlinear regularity010307 mathematical physicsGeometry and TopologyNonlinear maximum principleStrong comparison principlestrong comparison principleAnalysis of PDEs (math.AP)
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An automatic L1-based regularization method for the analysis of FFC dispersion profiles with quadrupolar peaks

2023

Fast Field-Cycling Nuclear Magnetic Resonance relaxometry is a non-destructive technique to investigate molecular dynamics and structure of systems having a wide range of ap- plications such as environment, biology, and food. Besides a considerable amount of liter- ature about modeling and application of such technique in specific areas, an algorithmic approach to the related parameter identification problem is still lacking. We believe that a robust algorithmic approach will allow a unified treatment of different samples in several application areas. In this paper, we model the parameters identification problem as a con- strained L 1 -regularized non-linear least squares problem. Following…

Computational Mathematicsparameter identificationSettore MAT/08 - Analisi NumericaFast Field Cycling NMR relaxationSettore ING-IND/30 - Idrocarburi E Fluidi Del SottosuoloApplied MathematicsFree-modelSettore AGR/13 - Chimica Agrarianon-linear Gauss-Seidel methodquadrupole relaxation enhancementL 1 regularizationSettore CHIM/06 - Chimica OrganicaSettore CHIM/02 - Chimica Fisica
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CRISPR sequences are sometimes erroneously translated and can contaminate public databases with spurious proteins containing spaced repeats

2020

© The Author(s) 2020.

Computer scienceGene predictionGenomicscomputer.software_genreGeneral Biochemistry Genetics and Molecular BiologyHomology (biology)03 medical and health sciencesAnnotation0302 clinical medicineCRISPRClustered Regularly Interspaced Short Palindromic RepeatsDatabases Protein030304 developmental biology0303 health sciencesDatabasePalindromeProteinsComputational geneGenomicsAcademicSubjects/SCI00960Original ArticleUniProtGeneral Agricultural and Biological Sciencescomputer030217 neurology & neurosurgeryInformation Systems
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Group Nonnegative Matrix Factorization with Sparse Regularization in Multi-set Data

2021

Constrained joint analysis of data from multiple sources has received widespread attention for that it allows us to explore potential connections and extract meaningful hidden components. In this paper, we formulate a flexible joint source separation model termed as group nonnegative matrix factorization with sparse regularization (GNMF-SR), which aims to jointly analyze the partially coupled multi-set data. In the GNMF-SR model, common and individual patterns of particular underlying factors can be extracted simultaneously with imposing nonnegative constraint and sparse penalty. Alternating optimization and alternating direction method of multipliers (ADMM) are combined to solve the GNMF-S…

Computer scienceGroup (mathematics)020206 networking & telecommunications02 engineering and technologySparse approximationNon-negative matrix factorizationSet (abstract data type)Constraint (information theory)Computer Science::Computer Vision and Pattern Recognition0202 electrical engineering electronic engineering information engineeringSource separation020201 artificial intelligence & image processingJoint (audio engineering)Sparse regularizationAlgorithm2020 28th European Signal Processing Conference (EUSIPCO)
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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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