1435 research outputs found
Sort by
Un progetto di restauro urbano. Il nuovo Calambrone di Pisa si confronta con la storia
Get PDFPresentazione del progetto di recupero urbano del litorale pisano denominato Calambrone con particolare attenzione alla valorazzazione del patrimonio architettonico delle colonie marine realizzate tra il 1932 ed il 1940
Theta-dependence of the spectrum of SU(N) gauge theories
No full textWe study the theta dependence of the spectrum of four-dimensional SU(N) gauge
theories, where theta is the coefficient of the topological term in the
Lagrangian, for N>=3 and in the large-N limit. We compute the O(theta^2) terms
of the expansions around theta=0 of the string tension and the lowest glueball
mass, respectively sigma(theta) = sigma (1 + s_2 theta^2 + ...) and M(theta) =
M (1 + g_2 theta^2 + ...), where sigma and M are the values at theta=0. For
this purpose we use numerical simulations of the Wilson lattice formulation of
SU(N) gauge theories for N=3,4,6. The O(theta^2) coefficients turn out to be
very small for all N>=3. For example, s_2=-0.08(1) and g_2=-0.06(2) for N=3.
Their absolute values decrease with increasing N. Our results are suggestive of
a scenario in which the theta dependence in the string and glueball spectrum
vanishes in the large-N limit, at least for sufficiently small values of
|theta|. They support the general large-N scaling arguments that indicate
(theta/N) as the relevant Lagrangian parameter in the large-N expansion
Analytical continuation from imaginary to real chemical potential in 2-color QCD under scrutiny
No full textThe method of analytical continuation from imaginary to real chemical
potential is tested in 2-color QCD. In comparison to previous studies in the
same theory, an exact updating algorithm is used and simulations are performed
closer to the thermodynamic limit. It is shown that the method considerably
improves if suitable functions are used to interpolate data with imaginary
chemical potential
Thesaurus per l'indice del titolario di classificazione delle università italiane
No full textQuesto lavoro nasce nell'ambito del progetto archivistico Titulus 97, promosso dall'Università di Padova con l'obiettivo di organizzare la gestione dei documenti prodotti dagli Atenei italiani, attraverso l'applicazione di un titolario di classificazione redatto secondo i criteri dettati dalla dottrina archivistica contemporanea. Si propone come strumento metodologico per coniugare l'esigenza archivistica di individuare le tipologie documentarie soggette a classificazione archivistica, attraverso una serie di voci di indice del titolario, con le metodologie di indicizzazione bibliotecarie
New approach to the treatment of separatrix chaos and its application to the global chaos onset between adjacent separatrices
No full textSUMMARY We have developed the {\it general method} for the description of {\it
separatrix chaos}, basing on the analysis of the separatrix map dynamics.
Matching it with the resonant Hamiltonian analysis, we show that, for a given
amplitude of perturbation, the maximum width of the chaotic layer in energy may
be much larger than it was assumed before. We apply the above theory to explain
the drastic facilitation of global chaos onset in time-periodically perturbed
Hamiltonian systems possessing two or more separatrices, previously discovered
(PRL 90, 174101 (2003)). The theory well agrees with simulations. We also
discuss generalizations and applications. Examples of applications of the
facilitation include: the increase of the DC conductivity in spatially periodic
structures, the reduction of activation barriers for noise-induced transitions
and the related acceleration of spatial diffusion, the facilitation of the
stochastic web formation in a wave-driven or kicked oscillator
Residenze universitarie e il ruolo delle istituzioni per valorizzare le periferie delle città
Get PDFResidenze Universitarie e il ruolo delle Istituzioni per valorizzare le periferie delle città. La realtà pisana e il piano di riqualificazione intercomunale tra Pisa e San Giuliano Terme
Alla ricerca di nuovi spazi comunicativi in biblioteca: Seminario 12 giugno 2006
No full textNel corso del seminario sono stati indicati nuovi spazi comunicativi, fisici e strutturali presenti nelle biblioteche postmoderne. During the seminar have been indicated new communicative, physical and structural spaces of the postmodern libraries
Dal museo al memoriale
Get PDFIn questo articolo si esaminano il Museo ebraico di Berlino, progettato da Daniel Libeskind, e il Memoriale agli Ebrei d'Europa uccisi, progettato da Peter Eisenman. Si pone attenzione sia alla loro architettura, sia al rapporto tra contenitore e contenuto, tra evocazione e ricostruzione storica di eventi drammatici, tra problemi museologici e espressività simbolica dell'architettura
Topology on the Lattice
No full textWe review the method developed in Pisa to determine the topological
susceptibility in lattice QCD and present a collection of new and old results
obtained by the method
Long-term planning versus short-term planning in the asymptotical location problem
No full textSUMMARY Given the probability measure over the given region , we consider the optimal location of a set composed by
points \Om in order to minimize the average distance \Sigma\mapsto \int_\Om
\dist(x,\Sigma) d\nu (the classical optimal facility location problem). The
paper compares two strategies to find optimal configurations: the long-term one
which consists in placing all points at once in an optimal position, and
the short-term one which consists in placing the points one by one adding at
each step at most one point and preserving the configuration built at previous
steps. We show that the respective optimization problems exhibit qualitatively
different asymptotic behavior as , although the optimization costs
in both cases have the same asymptotic orders of vanishing