Dynamics of the heat semigroup in Jacobi analysis

Let $\Delta$ be the Jacobi Laplacian. We study the chaotic and hypercyclic behaviour of the strongly continuous semigroups of operators generated by perturbations of $\Delta$ with a multiple of the identity on $L^p$ spaces

Paley--Wiener Theorems for the U(n)--spherical transform on the Heisenberg group

We prove several Paley--Wiener-type theorems related to the spherical transform on the Gelfand pair $\big(H_n\rtimes U(n),U(n)\big)$, where $H_n$ is the $2n+1$-dimensional Heisenberg group. Adopting the standard realization of the Gelfand spectrum as the Heisenberg fan in ${\mathbb R}^2$, we prove that spherical transforms of $U(n)$--invariant functions and distributions with compact support in $H_n$ admit unique entire extensions to ${\mathbb C}^2$, and we find real-variable characterizations of such transforms. Next, we characterize the inverse spherical transforms of compactly supported functions and distributions on the fan, giving analogous characterizations

Uniformly bounded representations and completely bounded multipliers of SL(2,R)

We estimate the norms of many matrix coefficients of irreducible uniformly bounded representations of SL(2, R) as completely bounded multipliers of the Fourier algebra. Our results suggest that the known inequality relating the uniformly bounded norm of a representation and the completely bounded norm of its coefficients may not be optimal

Weight of risk factors for mortality and short-term mortality displacement during the COVID-19 pandemic.

Background: We conducted a population-based cohort study to estimate mortality before, during and after the COVID-19 peak and to compare mortality in 2020 with rates reported in previous years, with a view to helping decision makers to apply containment measures for high-risk groups. Methods: All deaths were collected between 2015 and 2020 from municipal registry database. In 2020, weeks 1-26 were stratified in three periods: before, during and after the COVID mortality peak. The Poisson Generalized Linear regression Model showed the “harvesting effect”. Three logistic regressions for 8 dependent variables (age and comorbidities) and a t-test of  differences described all-cause mortality risk factors in 2019 and 2020 and differences between COVID and non-COVID patients. Results: A total of 47,876 deaths were collected. All-cause deaths increased by 38.5% during the COVID peak and decreased by 18% during the post-peak period in comparison with the average registered during the control period (2015-19), with significant mortality displacement in 2020. Except for chronic renal injuries in subjects aged 45-64 years, diabetes and chronic cardiovascular diseases in those aged 65-84 years, and neuropathies in those aged >84 years, the weight of comorbidities in deaths was similar or lower in COVID subjects than in non-COVID subjects. Discussions: Surprisingly, the weight of comorbidities in death, compared to weight in non-COVID subjects allows you to highlight some surprising results such as COPD, IBD and Cancer. The excess mortality that we observed in the entire period were modest in comparison with initial estimates during the peak, owing to the mild influenza season and the harvesting effect starting from the second half of May.   &nbsp

L'Irlande et l'intégration européenne

The participation of the Republic of lreland in the european integration brought into question certain aspects of the 1937 Constitution which established a State with a vigorous affirmation toward national sovereignity and international independence, which at the same time reflected a society of traditional catholic values. After joining the European Communities in 1972 and signing both the Single European Act in 1986 and the Treaty on European Union in 1992, Ireland proved itself to be an important actor in the european integration process. In each of these importants events constitutional amendments were introduced to permit the ratification of the treaties and eliminate all obstacles to allow community law to prevail over national law. In all three cases a necessary referendum proved strong support among the Irish people, for the european ideal. Sometimes however, the enthusiasm of political forces had to be balanced with difficult questions concerning legal and constitutional matters having profound implications for the social political context of the country.La participation de l'Irlande à la construction européenne a nécessairement remis en cause certains aspects de la Constitution de 1937 qui avait mis en place un État marqué par une vigoureuse affirmation de la souveraineté nationale et de l'indépendance dans l'ordre international et qui reflétait les caractéristiques d'une société fortement inspirée des valeurs traditionnelles et de la doctrine catholique. Après l'adhésion aux Communautés européennes en 1972, la signature de l'Acte Unique Européen de 1986 et du Traité sur l'Union européenne de 1992 ont marqué les étapes principales du processus d'intégration européenne dont l'Irlande a été un des acteurs les plus engagés. A l'occasion de chacune de ces trois étapes des amendements constitutionnels ont été nécessaires pour permettre la ratification des traités et éliminer tout obstacle à la pleine efficacité juridique du droit communautaire sur le plan interne. Dans les trois cas la consultation populaire par référendum a montré un fort soutien du peuple (celui à qui la Constitution appartient) à l'idée de l'Europe. Mais parfois l'« élan communautaire » manifesté par les forces politiques a dû tenir compte des problèmes d'ordre juridique et constitutionnel ayant aussi des implications profondes dans le contexte politique et social du pays.Astengo Francesca. L'Irlande et l'intégration européenne. In: Revue internationale de droit comparé. Vol. 49 N°3, Juillet-septembre 1997. pp. 657-677

"Open questions in the relation between national and community systems: The Italian case"

The assumption of this paper is that with the launch of the Convention created by the Declaration of the December 2001 European Council of Laeken, a "constituent" process for the European Union is in place. What does this imply for the Italian system? What kind of relationship can be envisaged between the Italian and the European legal orders? What of the role for the Constitutional Court? Are the constitutional instruments regulating the Italian participation in European construction appropriate? These are some of the questions that this paper will try to address in the following pages. In the first part, some of the elements which might contribute to define the current process as "constituent" will be emphasized; in the second part, the particular relationship between the Italian and EU systems, as well as the peculiar relationship (or non-relationship) between the Constitutional Court on one side, and the European Court of justice on the other, will be recalled in order to address the questions surrounding the novelty represented by the Constitutional Court's decision 135/2002; finally, some points of reflection concerning the constitutional treatment of the Italian participation in the European process of integration and the role of the Constitutional Court will be suggested

Moltiplicatori su estensioni armoniche di gruppi di tipo Heisenberg

Dottorato di ricerca in matematica. 7. ciclo. A.a. 1991-95. Coordinatore F. ArzarelloConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal