4,846 research outputs found
The smart city. Critical reading of a multiform phenomenon
Sempre più frequentemente la smart city è al centro dei discorsi delle differenti discipline. Cosa
s’intende, però, con l’espressione “città intelligente”? A quali ambiti si riferisce l’intelligenza
annunciata? In questo elaborato ci si sofferma specificamente sullo studio della smart city
declinata secondo i suoi principali obiettivi sociali, al fine di individuare e sottoporre ad analisi
critica le variabili costituenti il rapporto tra cittĂ intelligente e intenti annunciati. Come
coniugare, cioè, i molteplici obiettivi della smart city? All’interno di quali categorie pensare la
relazione tra città intelligente e obiettivi quali l’inclusione e lo sviluppo sociale? Attraverso che
tipo di misure raggiungere tali finalità ? Ci si sofferma, quindi, sul criterio dell’efficienza come
cifra fondamentale della rappresentazione della città intelligente e sulle criticità che l’equazione
smart city=efficienza comporta in termini di coesione del tessuto sociale. L’analisi si focalizza,
inoltre, sui criteri del bene comune e della relazionalitĂ come possibili categorie in grado di
coadiuvare le dinamiche del processo inclusivo
Invariant envelopes of holomorphy in the complexification of a Hermitian symmetric space
In this paper we investigate invariant domains in , a distinguished
-invariant, Stein domain in the complexification of an irreducible
Hermitian symmetric space . The domain , recently introduced by
Kr\"otz and Opdam, contains the crown domain and it is maximal with
respect to properness of the -action. In the tube case, it also contains
, an invariant Stein domain arising from the compactly causal structure
of a symmetric orbit in the boundary of . We prove that the envelope of
holomorphy of an invariant domain in , which is contained neither in
nor in , is univalent and coincides with . This fact,
together with known results concerning and , proves the
univalence of the envelope of holomorphy of an arbitrary invariant domain in
and completes the classification of invariant Stein domains
therein.Comment: 24 page
Maximal Complexifications of Certain Riemannian Homogeneous Manifolds
A characterization of maximal domains of existence of adapted complex
structures for Riemannian homogeneous manifolds under certain extensibility
assumptions on their geodesic flow is given. This is applied to generalized
Heisenberg groups and naturally reductive Riemannian homogeneous spaces. As an
application it is shown that the case of generalized Heisenberg groups yields
examples of maximal domains of definition for the adapted complex structure
which are are neither holomorphically separable, nor holomorphically convex.Comment: 18 pages, LaTeX-fil
Adaptive gravitational softening in GADGET
Cosmological simulations of structure formation follow the collisionless
evolution of dark matter starting from a nearly homogeneous field at early
times down to the highly clustered configuration at redshift zero. The density
field is sampled by a number of particles in number infinitely smaller than
those believed to be its actual components and this limits the mass and spatial
scales over which we can trust the results of a simulation. Softening of the
gravitational force is introduced in collisionless simulations to limit the
importance of close encounters between these particles. The scale of softening
is generally fixed and chosen as a compromise between the need for high spatial
resolution and the need to limit the particle noise. In the scenario of
cosmological simulations, where the density field evolves to a highly
inhomogeneous state, this compromise results in an appropriate choice only for
a certain class of objects, the others being subject to either a biased or a
noisy dynamical description. We have implemented adaptive gravitational
softening lengths in the cosmological simulation code GADGET; the formalism
allows the softening scale to vary in space and time according to the density
of the environment, at the price of modifying the equation of motion for the
particles in order to be consistent with the new dependencies introduced in the
system's Lagrangian. We have applied the technique to a number of test cases
and to a set of cosmological simulations of structure formation. We conclude
that the use of adaptive softening enhances the clustering of particles at
small scales, a result visible in the amplitude of the correlation function and
in the inner profile of massive objects, thereby anticipating the results
expected from much higher resolution simulations.Comment: 15 pages, 21 figures, 1 table. Accepted for publication in MNRA
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