Search results for "Matematica"

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.

Nonexistence Results for Higher Order Fractional Differential Inequalities with Nonlinearities Involving Caputo Fractional Derivative

2021

Higher order fractional differential equations are important tools to deal with precise models of materials with hereditary and memory effects. Moreover, fractional differential inequalities are useful to establish the properties of solutions of different problems in biomathematics and flow phenomena. In the present work, we are concerned with the nonexistence of global solutions to a higher order fractional differential inequality with a nonlinearity involving Caputo fractional derivative. Namely, using nonlinear capacity estimates, we obtain sufficient conditions for which we have no global solutions. The a priori estimates of the structure of solutions are obtained by a precise analysis …

On finite involutive Yang–Baxter groups

2021

[EN] A group G is said to be an involutive Yang¿Baxter group, or simply an IYB-group, if it is isomorphic to the permutation group of an involutive, nondegenerate set-theoretic solution of the Yang-Baxter equation. We give new sufficient conditions for a group that can be factorised as a product of two IYB-groups to be an IYB-group. Some earlier results are direct consequences of our main theorem.

The role of age and emotional valence in word recognition: an ex-gaussian analysis

2015

[Otro] Cie¿om práce je posúdi¿ vplyv veku a emo¿nej valencie na znovupoznávanie slov v rámci ex-Gaussových distribu¿ných komponentov. Dvom vekovým skupinám sme administrovali test znovupoznávania slov, v ktorom sme manipulovali emo¿nou valenciou. U mladších respondentov sa prejavili štatisticky signifikantné rozdiely pri negatívnych slovách v experimentálnej podmienke a v podmienke s distrakciou. U starších respondentov sme v odpove¿ových ¿asoch nezistili jasnú tendenciu. Vzh¿adom na ex-Gaussovský parameter ¿, ktorý sa v literatúre ¿asto spája s nárokmi na pozornos¿, vekovo podmienené rozdiely v emo¿nej valencii nemali žiaden vplyv na negatívne slová. Ak sa zameriame na emo¿nú valenciu v ob…

Quantizations from reproducing kernel spaces

2012

Abstract The purpose of this work is to explore the existence and properties of reproducing kernel Hilbert subspaces of L 2 ( C , d 2 z / π ) based on subsets of complex Hermite polynomials. The resulting coherent states (CS) form a family depending on a nonnegative parameter s . We examine some interesting issues, mainly related to CS quantization, like the existence of the usual harmonic oscillator spectrum despite the absence of canonical commutation rules. The question of mathematical and physical equivalences between the s -dependent quantizations is also considered.

Fixed point theorems for twisted (α,β)-ψ-contractive type mappings and applications

2013

The purpose of this paper is to discuss the existence and uniqueness of fixed points for new classes of mappings defined on a complete metric space. The obtained results generalize some recent theorems in the literature. Several applications and interesting consequences of our theorems are also given.

Nonstandard variational calculus with applications to classical mechanics. 1. An existence criterion

1999

Using the framework of nonstandard analysis, I find the discretized version of the Euler-Lagrange equation for classical dynamical systems and discuss the existence of an extremum for a given functional in variational calculus. Some results related to the Cauchy existence theorem are obtained and discussed with various examples.

La costituzione di un archivio digitale per i modelli di superfici dell’Università “Federico II” di Napoli

2013

Coupled fixed point results in cone metric spaces for -compatible mappings

2011

In this paper, we introduce the concepts of -compatible mappings, b-coupled coincidence point and b-common coupled fixed point for mappings F, G : X × X → X, where (X, d) is a cone metric space. We establish b-coupled coincidence and b-common coupled fixed point theorems in such spaces. The presented theorems generalize and extend several well-known comparable results in the literature, in particular the recent results of Abbas et al. [Appl. Math. Comput. 217, 195-202 (2010)]. Some examples are given to illustrate our obtained results. An application to the study of existence of solutions for a system of non-linear integral equations is also considered. 2010 Mathematics Subject Classificati…

Fixed point theorems for α-set-valued quasi-contractions in b-metric spaces

2015

Recently, Samet et al. [B. Samet, C. Vetro and P. Vetro, Fixed point theorems for alpha-psi-contractive type mappings, Nonlinear Anal., 75 (2012), 2154-2165] introduced the notion of alpha-psi-contractive mappings and established some fixed point results in the setting of complete metric spaces. In this paper, we introduce the notions of alpha-set-valued contraction and alpha-set-valued quasi-contraction and we give some fixed point theorems for such classes of mappings in the setting of b-metric spaces and ordered b-metric spaces. The presented theorems extend, unify and generalize several well-known comparable results in the existing literature.