Search results for "Number"

showing 10 items of 3939 documents

Experimental and theoretical studies of Λ doublings and permanent electric dipoles in the low-lying Π1 states of NaCs

2006

We present experimental data on the electric permanent dipole moments d(v',J') and lambda splittings (q factors) in the quasidegenerate (3) 1pi(e/f) state of the NaCs molecule over a wide range of the vibrational (v') and rotational (J') quantum numbers by using the combination of dc Stark mixing and electric radio frequency-optical double resonance methods. Within the experimental (3) 1pi state v' ranged from v' = 0 to 34, q values exhibited a pronounced decrease from 7.91x10(-6) to 0.47x10(-6) cm(-1), while absolute value(d) values varied between 8.0 and 5.0 D. Experimental evaluation yielded small d values about 1 D for D2 1pi state v'3 levels. The experiment is supported by ab initio el…

DipoleElectric dipole momentAb initio quantum chemistry methodsChemistryAb initioGeneral Physics and AstronomyElectronic structurePhysical and Theoretical ChemistryPerturbation theoryAtomic physicsQuantum numberPotential energyThe Journal of Chemical Physics
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Shear moduli of two dimensional binary glasses

2012

The shear moduli of two-component glasses in two dimensions are studied within mode coupling theory. Varying the concentration, strong mixing effects are observed along the glass transition lines for two interaction potentials. Nonoverlapping disks with size ratios between 0.3 and 0.9, and point particles interacting with (magnetic) dipoles of strength ratio between 0.1 and 0.6 are considered. Equilibrium structure factors (partially obtained from Monte Carlo simulations) and glass form factors, and perturbative calculations show that a softening of the elastic shear constant of glass upon adding another component arises from a dilution effect of the majority component. For very disparate m…

DipoleMaterials scienceShear (geology)Condensed matter physicsMonte Carlo methodMode couplingBinary numberddc:530General ChemistryCondensed Matter PhysicsGlass transitionSofteningModuli
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Weakened acute type condition for tetrahedral triangulations and the discrete maximum principle

2000

We prove that a discrete maximum principle holds for continuous piecewise linear finite element approximations for the Poisson equation with the Dirichlet boundary condition also under a condition of the existence of some obtuse internal angles between faces of terahedra of triangulations of a given space domain. This result represents a weakened form of the acute type condition for the three-dimensional case.

Dirichlet problemAlgebra and Number TheoryDiscretizationApplied MathematicsMathematical analysisDomain (mathematical analysis)Piecewise linear functionComputational Mathematicssymbols.namesakeMaximum principleDirichlet boundary conditionsymbolsBoundary value problemPoisson's equationMathematicsMathematics of Computation
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Radial solutions of Dirichlet problems with concave-convex nonlinearities

2011

Abstract We prove the existence of a double infinite sequence of radial solutions for a Dirichlet concave–convex problem associated with an elliptic equation in a ball of R n . We are interested in relaxing the classical positivity condition on the weights, by allowing the weights to vanish. The idea is to develop a topological method and to use the concept of rotation number. The solutions are characterized by their nodal properties.

Dirichlet problemNon lineariteApplied MathematicsMathematical analysisRegular polygonRadial solutions Multiplicity results Dirichlet concave–convex problem Rotation numberDirichlet distributionElliptic curveNonlinear systemsymbols.namesakesymbolsBall (mathematics)AnalysisRotation numberMathematics
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On the Sets of Regularity of Solutions for a Class of Degenerate Nonlinear Elliptic Fourth-Order Equations with L1 Data

2007

We establish Holder continuity of generalized solutions of the Dirichlet problem, associated to a degenerate nonlinear fourth-order equation in an open bounded set , with data, on the subsets of where the behavior of weights and of the data is regular enough.

Dirichlet problemPartial differential equationAlgebra and Number TheoryBounded setDifferential equationMathematical analysisDegenerate energy levelsgrowth conditionElliptic equationlcsh:QA299.6-433lcsh:AnalysisRenormalized solutionNonlinear systemSimultaneous equationsOrdinary differential equationAnalysisMathematicsBoundary Value Problems
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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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Planar maps whose second iterate has a unique fixed point

2007

Let a>0, F: R^2 -> R^2 be a differentiable (not necessarily C^1) map and Spec(F) be the set of (complex) eigenvalues of the derivative F'(p) when p varies in R^2. (a) If Spec(F) is disjoint of the interval [1,1+a[, then Fix(F) has at most one element, where Fix(F) denotes the set of fixed points of F. (b) If Spec(F) is disjoint of the real line R, then Fix(F^2) has at most one element. (c) If F is a C^1 map and, for all p belonging to R^2, the derivative F'(p) is neither a homothety nor has simple real eigenvalues, then Fix(F^2) has at most one element, provided that Spec(F) is disjoint of either (c1) the union of the number 0 with the intervals ]-\infty, -1] and [1,\infty[, or (c2) t…

Discrete mathematics37G10; 37G15; 34K18Algebra and Number TheoryApplied Mathematics37G15Dynamical Systems (math.DS)Fixed point37G10Homothetic transformationPlanar graphSet (abstract data type)symbols.namesakeMathematics - Classical Analysis and ODEsSimple (abstract algebra)Classical Analysis and ODEs (math.CA)FOS: MathematicssymbolsEmbeddingDifferentiable functionMathematics - Dynamical Systems34K18AnalysisEigenvalues and eigenvectorsMathematicsJournal of Difference Equations and Applications
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On the additivity of block designs

2016

We show that symmetric block designs $${\mathcal {D}}=({\mathcal {P}},{\mathcal {B}})$$D=(P,B) can be embedded in a suitable commutative group $${\mathfrak {G}}_{\mathcal {D}}$$GD in such a way that the sum of the elements in each block is zero, whereas the only Steiner triple systems with this property are the point-line designs of $${\mathrm {PG}}(d,2)$$PG(d,2) and $${\mathrm {AG}}(d,3)$$AG(d,3). In both cases, the blocks can be characterized as the only k-subsets of $$\mathcal {P}$$P whose elements sum to zero. It follows that the group of automorphisms of any such design $$\mathcal {D}$$D is the group of automorphisms of $${\mathfrak {G}}_\mathcal {D}$$GD that leave $$\mathcal {P}$$P in…

Discrete mathematicsAlgebra and Number Theory010102 general mathematics0102 computer and information sciencesAutomorphism01 natural sciencesCombinatorics010201 computation theory & mathematicsAdditive functionDiscrete Mathematics and CombinatoricsSettore MAT/03 - Geometria0101 mathematicsInvariant (mathematics)Symmetric designAbelian groupBlock designs Symmetric block designs Hadamard designs Steiner triple systemsMathematicsJournal of Algebraic Combinatorics
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On ergodic operator means in Banach spaces

2016

We consider a large class of operator means and prove that a number of ergodic theorems, as well as growth estimates known for particular cases, continue to hold in the general context under fairly mild regularity conditions. The methods developed in the paper not only yield a new approach based on a general point of view, but also lead to results that are new, even in the context of the classical Cesaro means.

Discrete mathematicsAlgebra and Number Theory010102 general mathematicsContext (language use)010103 numerical & computational mathematicsFinite-rank operatorShift operatorCompact operator01 natural sciencesStrictly singular operatorFunctional Analysis (math.FA)Mathematics - Functional AnalysisOperator (computer programming)Multiplication operatorFOS: MathematicsErgodic theory0101 mathematicsAnalysisMathematics
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Approximate fixed points of set-valued mapping in b-metric space

2016

We establish existence results related to approximate fixed point property of special types of set-valued contraction mappings, in the setting of b-metric spaces. As consequences of the main theorem, we give some fixed point results which generalize and extend various fixed point theorems in the existing literature. A simple example illustrates the new theory. Finally, we apply our results to establishing the existence of solution for some differential and integral problems.

Discrete mathematicsAlgebra and Number Theory010102 general mathematicsb-metric space η-contraction fixed point theorem integral inclusionFixed point01 natural sciences010101 applied mathematicsSet (abstract data type)Metric spaceSettore MAT/05 - Analisi MatematicaSettore MAT/03 - Geometria0101 mathematicsComposite materialAnalysisMathematics
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