Search results for " Analisi"

Extensions of positive linear functionals on a *-algebra

2010

The family of all extensions of a nonclosable hermitian positive linear functional defined on a dense *-subalgebra $\Ao$ of a topological *-algebra $\A[\tau]$ is studied with the aim of finding extensions that behave regularly. Under suitable assumptions, special classes of extensions (positive, positively regular, absolutely convergent) are constructed. The obtained results are applied to the commutative integration theory to recover from the abstract setup the well-known extensions of Lebesgue integral and, in noncommutative integration theory, for introducing a generalized non absolutely convergent integral of operators measurable w. r. to a given trace $\sigma$.

ANALISI DI RISCHIO DELL’IMPIANTO SPERIMENTALE “SELECTIVE PRODUCTION OF EXOTIC SPECIES” (SPES) DELL’INFN DI LEGNARO

Il progetto di ricerca denominato EURISOL (European Isotope Separation On-Line Radioactive Ion Beam Facility), che vede coinvolti i principali laboratori di ricerca nucleari europei, è rivolto allo studio di progettazione e fattibilità di un impianto per la produzione di fasci di nuclei radioattivi posizionati nella cosiddetta “terra incognita” della carta dei nuclidi. Lo scopo principale è l’esplorazione della materia esotica (nuclei caratterizzati da un eccesso difetto di neutroni), con le sue possibili implicazioni nell’ambito della ricerca di base della fisica nucleare, nelle applicazioni in campo medico e dell’astrofisica, e ancora nello studio dei materiali utilizzati nei reattori nuc…

Gradient estimates for the perfect conductivity problem in anisotropic media

2018

Abstract We study the perfect conductivity problem when two perfectly conducting inclusions are closely located to each other in an anisotropic background medium. We establish optimal upper and lower gradient bounds for the solution in any dimension which characterize the singular behavior of the electric field as the distance between the inclusions goes to zero.

On the first return integrals

2007

Some pathological properties of the first-return integrals are explored. In particular it is proved that there exist Riemann improper integrable functions which are first-return recoverable almost everywhere, but not first-return integrable, with respect to each trajectory. It is also proved that the usual convergence theorems fail to be true for the first-return integrals.

Fixed point theorems for $\alpha$-$\psi$-contractive type mappings

2012

In this paper, we introduce a new concept of $\alpha$-$\psi$-contractive type mappings and establish fixed point theorems for such mappings in complete metric spaces. Starting from the Banach contraction principle, the presented theorems extend, generalize and improve many existing results in the literature. Moreover, some examples and applications to ordinary differential equations are given here to illustrate the usability of the obtained results.

I temi emersi dai focus group: percorsi di un’analisi sociologica

2011

Francesco Fichera e il Palazzo delle Poste per Noto: studio grafico su un edificio mai realizzato

2022

Si può parlare di dialogo in architettura? Il disegno può essere considerato come la traduzione in forma grafica dei rapporti dialogici in architettura e tra architettura e città? Con questo scritto si tenterà si rispondere ai due quesiti appena formulati attraverso lo studio del caso di un edificio non realizzato dell’architetto catanese Francesco Fichera (1881-1950) per la città emblema del barocco siciliano, Noto: il Palazzo delle Poste e Casa Littoria nella centralissima piazza del Municipio. L’approfondimento sulla documentazione progettuale ritrovata e la successiva fase di ridisegno critico restituiscono una possibile chiave di lettura su un metodo compositivo fortemente ancorato a r…

Locally convex quasi *-algebras with sufficiently many *-representations

2012

AbstractThe main aim of this paper is the investigation of conditions under which a locally convex quasi ⁎-algebra (A[τ],A0) attains sufficiently many (τ,tw)-continuous ⁎-representations in L†(D,H), to separate its points. Having achieved this, a usual notion of bounded elements on A[τ] rises. On the other hand, a natural order exists on (A[τ],A0) related to the topology τ, that also leads to a kind of bounded elements, which we call “order bounded”. What is important is that under certain conditions the latter notion of boundedness coincides with the usual one. Several nice properties of order bounded elements are extracted that enrich the structure of locally convex quasi ⁎-algebras.

On the Consistency Restoring in SPH

2009

Fuzzy fixed points of generalized F2-geraghty type fuzzy mappings and complementary results

2016

The aim of this paper is to introduce generalized F2-Geraghty type fuzzy mappings on a metric space for establishing the existence of fuzzy fixed points of such mappings. As an application of our result, we obtain the existence of common fuzzy fixed point for a generalized F2-Geraghty type fuzzy hybrid pair. These results unify, generalize and complement various known comparable results in the literature. An example and an application to theoretical computer science are presented to support the theory proved herein. Also, to suggest further research on fuzzy mappings, a Feng–Liu type theorem is proved.