Search results for "topologia"

Interest-based topology management in unstructured peer-to-peer networks

2012

Generalized distance-squared mappings of the plane into the plane

2016

Abstract We define generalized distance-squared mappings, and we concentrate on the plane to plane case. We classify generalized distance-squared mappings of the plane into the plane in a recognizable way.

Heisenberg quasiregular ellipticity

2016

Following the Euclidean results of Varopoulos and Pankka--Rajala, we provide a necessary topological condition for a sub-Riemannian 3-manifold $M$ to admit a nonconstant quasiregular mapping from the sub-Riemannian Heisenberg group $\mathbb{H}$. As an application, we show that a link complement $S^3\backslash L$ has a sub-Riemannian metric admitting such a mapping only if $L$ is empty, the unknot or Hopf link. In the converse direction, if $L$ is empty, a specific unknot or Hopf link, we construct a quasiregular mapping from $\mathbb{H}$ to $S^3\backslash L$. The main result is obtained by translating a growth condition on $\pi_1(M)$ into the existence of a supersolution to the $4$-harmonic…

On the topology of surfaces with the generalised simple lift property.

2020

In this paper, we study the geometry of surfaces with the generalised simple lift property. This work generalises previous results by Bernstein and Tinaglia, and it is motivated by the fact that leaves of a minimal lamination obtained as a limit of a sequence of properly embedded minimal disks satisfy the generalised simple lift property.

Mente e identita-in-rete nell’era di facebook.

2011

Creazione di collegamenti a scambio di informazione nei social network. Una simulazione agent-based con metodologia soft computing.

2015

La robustezza di una rete sociale dipende da caratteristiche intrinseche della  sua  topologia,  quali  ad  esempio  l’invarianza  di  scala,  la  presenza  di   nodi denominati hub (i nodi più popolari del network, Barabási e Albert 1999), una distribuzione di probabilità esponenziale, come quella illustrata in Figura 1, nel grado dei vertici P(x) =x^(-α)  con  fattore α  compreso  tra 2  e 3,  (come  quella  descritta  da  Albert  e  Barabási  2002);  ma  l’origine  di  queste  caratteristiche va ricercata come emergente dal comportamento dei singoli componenti della rete, e non necessariamente nel suo complesso (in tal senso è emblematico il caso del World Wide Web, come descritto in Alb…

Detecting topology through dynamics in interacting fermionic wires

2020

We describe a protocol to read out the topological invariant of interacting 1D chiral models, based on measuring the mean chiral displacement of time-evolving bulk excitations. We present analytical calculations and numerical Matrix Product State simulations of interacting Su-Schrieffer-Heeger (SSH) chains, demonstrating how the mean chiral displacement allows to distinguish between topological insulator, trivial insulator and symmetry-broken phases. Finally, we provide an experimental blueprint for realizing a model displaying these three phases and describe how to detect those.

Intrinsic characterization of space‐time symmetric tensors

1992

This paper essentially deals with the classification of a symmetric tensor on a four‐dimensional Lorentzian space. A method is given to find the algebraic type of such a tensor. A system of concomitants of the tensor is constructed, which allows one to know the causal character of the eigenspace corresponding to a given eigenvalue, and to obtain covariantly their eigenvectors. Some algebraic as well as differential applications are considered.

The Dark Side of the Port (Engl) - Il lato oscuro del Porto (Ita)

2013

Come la bouillabaisse, Marsiglia interpreta con autenticità e generosità la sua natura di città portuale: con gli ingredienti di mare, i condimenti del territorio e i suoi sapori multietnici fa capolavori; ma la stessa complessità della bouillabaisse, ai limiti della saturazione organolettica così troppo piena di sapori, è sempre troppo poco per contenere e raccontare tutta Marsiglia. Like bouillabaisse, Marseille authentically and generously express its nature of port city: it creates masterpieces using ingredients coming from the sea, seasonings from the land and its multiethnic flavors; however, the same complexity of bouillabaisse, at the limits of sensory saturation, too rich of flavor…

Free vs. Locally Free Kleinian Groups

2015

Abstract We prove that Kleinian groups whose limit sets are Cantor sets of Hausdorff dimension < < 1 are free. On the other hand we construct for any ε > > 0 an example of a non-free purely hyperbolic Kleinian group whose limit set is a Cantor set of Hausdorff dimension < < 1 + + ε.