Search results for "operators"
showing 10 items of 228 documents
A bounded version of bosonic creation and annihilation operators and their related quasi-coherent states
2007
Coherent states are usually defined as eigenstates of an unbounded operator, the so-called annihilation operator. We propose here possible constructions of {\em quasi-coherent states}, which turn out to be {\em quasi} eigenstate of a \underline{bounded} operator related to an annihilation-like operator. We use this bounded operator to construct a sort of modified harmonic oscillator and we analyze the dynamics of this oscillator from an algebraic point of view.
Spectra and essential spectral radii of composition operators on weighted Banach spaces of analytic functions
2008
AbstractWe determine the spectra of composition operators acting on weighted Banach spaces Hv∞ of analytic functions on the unit disc defined for a radial weight v, when the symbol of the operator has a fixed point in the open unit disc. We also investigate in this case the growth rate of the Koenigs eigenfunction and its relation with the essential spectral radius of the composition operator.
An extension of Guo's theorem via k--contractive retractions
2006
Abstract Let X be a infinite-dimensional Banach space. We generalize Guo's Theorem [D.J. Guo, Eigenvalues and eigenvectors of nonlinear operators, Chinese Ann. Math. 2 (1981) 65–80 [English]] to k- ψ -contractions and condensing mappings, under a condition which depends on the infimum k ψ of all k ⩾ 1 for which there exists a k- ψ -contractive retraction of the closed unit ball of the space X onto its boundary.
Fractional-order theory of thermoelasticicty. I: Generalization of the Fourier equation
2018
The paper deals with the generalization of Fourier-type relations in the context of fractional-order calculus. The instantaneous temperature-flux equation of the Fourier-type diffusion is generalized, introducing a self-similar, fractal-type mass clustering at the micro scale. In this setting, the resulting conduction equation at the macro scale yields a Caputo's fractional derivative with order [0,1] of temperature gradient that generalizes the Fourier conduction equation. The order of the fractional-derivative has been related to the fractal assembly of the microstructure and some preliminary observations about the thermodynamical restrictions of the coefficients and the state functions r…
Digitālās transformācijas projekts telekomunikāciju uzņēmumā
2018
Digitālā transformācija ir uzņēmuma spēja adaptēties tehnoloģiju progresam. Tas prasa organizācijām diversificēt ieņēmumus, mainīt biznesa modeli un attīstīt jaunus pakalpojumus, lai apgūtu augošu digitālo ekosistēmu, kurā mijiedarbojas sakari, tehnoloģijas un mediji. Maģistra darba tēma ir “Digitālās transformācijas projekts telekomunikāciju uzņēmumā”. Darba mērķis ir veicināt jaunu digitālo pakalpojumu attīstību Tele2 organizācijā, kas ļauj stiprināt digitālo transformāciju un potenciāli var palielināt uzņēmuma ieņēmumus nākotnē. Darbs sastāv no trīs nodaļām. Pirmā nodaļa ir projekta pētījums, kur autors analizē telekomunikāciju nozares attīstības globālos izaicinājumus un novērtē digitāl…
Lojalitātes programmas izstrāde mobilajam operatoram
2015
Maģistra darba tēma ir “Lojalitātes programmas izstrāde mobilajam operatoram”. Darba mērķis ir veicināt piedāvājumu dažādību Latvijas mobilo telekomunikāciju nozarē. Darbs ir strukturēts trīs daļās – izpētes daļā veikta telekomunikāciju nozares Latvijā izpēte, projekta priekšlikuma izstrādes daļā piedāvāti potenciālie alternatīvu varianti, kā risināt izvirzīto problēmu, izvēloties ekonomiski veiksmīgāko, projekta rokasgrāmatas izstrādes daļā izvēlētajai alternatīvai veikta detalizēta plānošana. Maģistra darba izstrādes rezultāts ir projekts, kas ietver lojalitātes programmas izstrādi ar četrām tās komponentēm.
Aggregation of fuzzy structures based on equivalence relations
2016
Elektroniskā versija nesatur pielikumus
Pseudodifferential operators of Beurling type and the wave front set
2008
AbstractWe investigate the action of pseudodifferential operators of Beurling type on the wave front sets. More precisely, we show that these operators are microlocal, that is, preserve or reduce wave front sets. Some consequences on micro-hypoellipticity are derived.
Relations between multi-resolution analysis and quantum mechanics
2005
We discuss a procedure to construct multiresolution analyses (MRA) of L2 (R) starting from a given seed function h (s) which should satisfy some conditions. Our method, originally related to the quantum mechanical Hamiltonian of the fractional quantum Hall effect, is shown to be model independent. The role of a canonical map between certain canonically conjugate operators is discussed. This clarifies our previous procedure and makes much easier most of the original formulas, producing a convenient framework to produce examples of MRA. © 2005 American Institute of Physics.
Viscoelasticity: an electrical point of view
2014
Time dependent hereditary properties of complex materials are well described by power-laws with real order exponent. This experimental observation and analogous electrical experiments, yield a description of these properties by using fractional-order operators. In this paper, elasto-viscous and visco-elastic behaviors of fractional order hereditary materials are firstly described by using fractional mathematical operators, based on recent work of some of the authors. Then, electrical analogous models are introduced. Viscoelastic models have elastic and viscous components which can be obtained by combining springs and dashpots: these models can be equivalently viewed as electrical circuits, …