Booklet presents research at UOS Sapienza

Physics of Complexity

The first booklet of UOS Sapienza with the description of many research topics for students and interested researchers… Read the rest

Physics of Complexity @ ISC-Sapienza – 17 Novembre 2014

Pomeriggio tematico sulle attività dell’UOS Sapienza the rest

Rules and Exceptions in Language Dynamics

In all languages, rules have exceptions in the form of irregularities. Since rules make a language efficient, the persistence of irregularity is an anomaly. How language systems become rule governed, how and why they sustain exceptions to rules? Frequent words are unlikely to change over time (e.g., frequent verbs tend to maintain an irregular past tense form). What is the role of frequency in maintaining exceptions to rules?… Read the rest

Mixing by degree in signed social networks

Social networks have empirically been found to be assortative (i.e., the degree of neighboring nodes are positively correlated), while other networks (e.g., technological, biological) show the opposite pattern (disassortative). Why is that so?
How do these patterns change in signed networks, where relations indicate trust/distrust, friendship/enmity? Do individuals who dislike many others tend to dislike each other, or do they dislike those who dislike only very few others?… Read the rest

Dynamics of Virus-Host interaction

In the case of fast mutating viruses (e.g., Influenza virus), the virus-host interaction is driven by cross-immunity: after being infected by a strain, the host acquires immunity to a set of other strains antigenically similar to the infecting one (i.e., triggering the same host immune response). The evolutionary dynamics of viruses is therefore ruled by their relative antigenic distance. Can we understand the non trivial relation between antigenic and genetic distance?… Read the rest

Fractures and crack propagation

The intermittent and self-similar fluctuations displayed by a slow crack during the propagation in a heterogeneous medium can be quantitatively described by an extension of a classical statistical model for fracture. The model yields the correct dynamical and morphological scaling, and allows to demonstrate that the scale invariance originates from the presence of a non-equilibrium, reversible, critical transition which, in the presence of dissipation, gives rise to self-organized critical behaviour.… Read the rest