NEWDFESCM

New density functionals for the electronic structure of correlated materials.

Funding Body: Italian Institute of Technology (IIT)
(2010-2013)
José Lorenzana
Correlated systems are poorly described by the local density approximation. The main aim of this project is to develop new … Read the rest

FOC

Forecasting Financial Crises.

Funding Body: European Union (FET Open) (2010-2013)
Guido Caldarelli

Partners: University of Ancona, ETH Zurich, University of Oxford, City University, Barcelona Media Lab, ECB

FOC is a Scientific Project Financed by FET OPEN Scheme in the field … Read the rest

LithIon

Hydrides as innovative anodes for lithium batteries

Funding Body: MIUR FIRB (2010) EURO: 19000 (2017)
Sergio Brutti & Annalisa PaoloneRead the rest

JIINL

Joint Italy-Israel Neural Lab

Funding Body: Ministero degli Affari Esteri (MAE)
(2010-2015) web site
Alessandro Torcini
This joint Italy-Israel collaborative effort is aimed to develop novel strategies for brain repair by integrating recent advances in Complex Network Theory, Nonlinear Data … Read the rest

Synchronization of extended systems

Synchronization is a long known phenomenon dating back to Huygens experiments who observed that suspending two pendula “…in the same wooden beam, the motions of each pendulum in opposite swings were so much in agreement that they never receded Read the rest

AFOSR

Three-dimensional reconstruction of individual trajectories within bird flocks and insect swarms

Funding Body: AirForce Office for Scientific Research – USA
(2010-2014 USD 400K)
Andrea Cavagna
The objective of this research is to uncover the fundamental principles and algorithms that govern … Read the rest

ARTSWARM

From self-organized animal groups to distributed artificial swarms: exporting natural behavioural rules to mobile robotics

Funding Body: Italian Institute of Technology (IIT) – Seed Project 2009
(2010-2013, EUR 650K)
Irene Giardina
The study of self-organization and collective behaviour encompasses fields … Read the rest

SWARM

Empirical analysis and theoretical modelling of self-organized collective behaviour in three-dimensions: from insect swarms and bird flocks to new schemes of distributed coordination

Funding Body: European Research Council – ERC Starting Grant 2010
(2010-2015, EUR 1.1M)
Irene Giardina
Collective phenomena … Read the rest

GRANULAR CHAOS

Granular fluids to explore non-equilibrium statistical mechanics.

Funding Body: MIUR, Italy (reserved to selected ERC-Starting Grants 2007)
(2009-2014) EURO: 1.2 M
Andrea Puglisi
GranularChaos is a theoretical and experimental project focused on understanding the connection between microscopic and mesoscopic … Read the rest

Statistical physics modeling of social dynamics

In recent years it has become widely recognized that many large-scale phenomena observed in social systems are the “macroscopic” complex effect of the “microscopic” simple behavior of a large number of interacting agents. This has led social scientists to the … Read the rest

Regularities and universality in large-scale social phenomena

In social phenomena every individual interacts with a limited number of peers, usually negligible as compared with the total number of people in the system. In spite of that, human societies are characterized by stunning global regularities. There are transitions … Read the rest

Fractal analysis of planetary topographies

There exists an overwhelming diversity of landscapes on Earth. A cornerstone of modern geomorphology came with the realization that all the different features of the terrestrial surface result from the accumulated effect of current geological agents [Lyell, 1830]. This principle … Read the rest

Polarons in strongly correlated systems

In system with strong electron-phonon interaction, the carriers loose mobility, ultimately acquiring polaronic character. A polaron is a state in which the phonon and electron degrees of freedom are strongly entangled, and the presence of an electron is associated to … Read the rest

GZIP: Galaxy morphology classification by zip algorithm

Even before the identification of galaxies as stellar systems, astronomers have classified them based on their visual appearance. Galaxies in the local universe can organized in a sequence of morphologies (e.g. the Hubble sequence) which must be the result of … Read the rest

Tidal tail characterization

Introduction

A globular cluster (GC) is a spherical collection of stars that orbits a galactic core as a satellite.
Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their … Read the rest

Spatially correlated random walks and turbulence

The wide applicability of the random walks (RW) to natural phenomena relies just on the possibility to introduce appropriate generalizations on the probabilistic nature of displacements. A straightforward generalization is realized by assuming correlations in displacements to obtain the so … Read the rest

Granular Gases to explore Non-Equilibrium Statistical Mechanics

How do properties of molecular trajectories reflect on large scale transport and relaxation properties? Is it possible to directly and experimentally verify the Boltzmann’s program, connecting the microscopic level to the macroscopic description? Can we zoom into an out-of-equilibrium fluid … Read the rest

Dynamics of self-gravitating systems

A System with long-range interactions is characterized by an inter-particle potential which decays at large distances with a power law exponent which is smaller than the dimension of the embedding space. Classical examples include for instance: self-gravitating systems, unscreened Coulomb … Read the rest

Matter density fields in the early universe

The most prominent feature of the initial conditions of the matter spatial distribution in the early universe, in standard theoretical models, derived from inflationary mechanisms, is that matter density field presents on large scale super-homogeneous features. This means the following. … Read the rest

Total gravitational force and the classification of long range interactions

In equilibrium statistical mechanics the distinction between short and long range interactions is given by the integrability or not of the pair potential. However for what concerns only the clustering dynamics of a particle distribution under the effect of an … Read the rest

Graphene and carbon-based new materials

The investigation of the electronic properties of graphene (single hexagonal layer of carbon atoms) has attracted a renewed interest after the development of recent techniques which permit to produce and manage single-layer (and also multilayer) samples of this materials. Nowadays … Read the rest

Role of microscopic chaos to macroscopic transport

The discovery that simple deterministic nonlinear systems could display dynamical evolution characterized by a randomness similar to stochastic processes changed very much researchers’ attitude toward determinism and predictability of natural phenomena. Determinstic chaos has been successfully invoked to interpret several … Read the rest

Disorder driven non-equilibrium phase transition: the Random field Ising model

In hard magnetic materials, the domain walls movement or even creation is suppressed, and other mechanisms, like domains nucleation and coherent spin rotation enter in the process of magnetization reversal. For these kind of materials a description in terms of … Read the rest

Systems with multiplicative noise

Problems susceptible to be mathematically represented by stochastic Langevin equations including a multiplicative noise abound not only in physics, but also in biology, ecology, economy, or social sciences. In a broad sense a Langevin equation is said to be multiplicative … Read the rest

Competing orders in Iron based superconductors

In January 2008 a new family of superconductors has been discovered with FeAs layers. Iron is a magnetic ion and in traditional superconductors small amounts of magnetic impurities kill superconductivity so an iron based superconductor is at first sight surprising.… Read the rest

COBBS – Publications

COBBS papers in collective behaviour:

Read the rest

Protein molecules

Biopolymers such as nucleic acids (DNA and RNA) and proteins have been charged by natural evolution with the task of storing, transmitting and transforming genetic information of living matter.
In particular proteins are the macromolecules which perform most of the … Read the rest

Metastable states and supersymmetry

Both the static and the dynamical behaviour occurring in mean field spin glass models models can be interpreted as consequences of the complex (free) energy landscape that spin glasses have, with many minima, valleys and saddles. Traditionally, much attention has … Read the rest

Field theory for finite dimensional spin glasses

Many features predicted by mean field spin glass models, such as the behaviour of susceptibilities and correlation functions or the occurrence of aging and off-equilibrium dynamics, are qualitatively observed in experiments, suggesting that the mean field scenario may hold for … Read the rest

Frustrated Phase Separation

A large variety of systems with competing short and long range interactions self-organizes in domain patterns as reviewed by Seul and Andelman. Examples range from magnetic systems (left figure A) to organic systems (left figure B).

Inhomogeneous states display a … Read the rest

The growth of amorphous order in supercooled liquids

Close to the glass transition supercooled liquids display an impressive increase of the relaxation time, without any clear sign of growing thermodynamic order, nor correlation length. This is at variance with physical intuition, which suggests that a large relaxation time … Read the rest

Polarons in organic single crystal FET’s

Organic field effect transistors (OFETs) are providing exciting prospects for potential applications in electronics. The active elements of these devices use “plastic” semiconductors, based on carbon and hydrogen. Among the advantages compared to classical silicon transistors, this new generation of … Read the rest

Crackling noise: the Barkhausen effect

The term “crackling noise” refers to the signal that some disordered systems produce as a response to an external driving field smoothly changing in time. Due to the presence of disorder, crackling signals are extremely irregular, despite the … Read the rest

Dynamic hysteresis in thin and ultra-thin films

The physics of thin and ultra-thin magnetic films has been extensively studied in the recent past, because of its important implications for applications to high frequency devices. Power losses in ferromagnetic materials generally depend on the frequency of the applied … Read the rest

Dynamical Processes on Networks

During the last decade it has become clear that the topology in many systems, ranging from technological to social to biological, is not well described by regular lattices nor by random graphs. Complex networks, characterized by small-world effects, large connectivity … Read the rest

Human Dynamics

Until now, the study of human dynamics has been done only qualitatively. Actually, the present possibility to have quantitative data on the kind and nature of social relationships through social networks is driving a rapid change in the field. Thanks … Read the rest

Unconventional antiferromagnetism due to Dzyaloshinskii-Moriya interactions

The relevance of antisymmetric superexchange interactions in spin Hamiltonians describing quantum antiferromagnetic (AF) systems has been acknowledged long ago by Dzyaloshinskii. Soon after, Moriya showed that such interactions arise naturally in perturbation theory due to the spin-orbit coupling in magnetic … Read the rest

Random Lasers

In a nutshell, a random laser is the coherent emission from active stochastic resonators.

In a series of articles around 1966, a Russian scientist V. S. Letokhov, of the Lebedev Physics Institute in Dubna considered the generation of light in … Read the rest

Strongly Correlated Superconductivity: how can repulsion enhance Tc?

In conventional superconductors, the repulsive interaction between electrons opposes to phonon-mediated pairing. We have shown that even phonon-mediated superconductivity can be favoured by repulsion under suitable conditions which are realized in fullerenes.

Trivalent alkali-doped fullerenes are almost certainly electron-phonon superconductors, … Read the rest

COBBS – Photographs

Here is a selection of some of the INFM-CNR photographs from the STARFLAG project.

They are at low resolution. You can have the high resolution versions by contacting Andrea Cavagna:

Please note that the credit for each one of Read the rest

The INFM-CNR/STARFLAG team

Here follows a very synthetic description of the role each one of the people in the INFM-CNR/STARFLAG team had:

  • Michele Ballerini (CNR-INFM)
    electronics, data taking
  • Nicola Cabibbo (La Sapienza)
    electronics design, experimental setup design
  • Raphael Candelier (La Sapienza and CEA)
Read the rest

Spin Glasses: a brief introduction

Spin Glasses are dilute magnetic alloys where the interactions between spins are randomly ferromagnetic or anti-ferromagnetic, and are considered as paradigmatic examples of frozen disorder. The presence of disorder (the random interactions) induces frustration and a greater difficulty for the … Read the rest

What is Econophysics?

Collective phenomena in economics, social sciences and ecology are very attractive for statistical physicists, especially in view of the empirical abundance of non-trivial fluctuation patterns and statistical regularities — think of returns in financial markets or of allometric scaling in … Read the rest

Spin-orbit interaction and spintronics

One of the new frontiers in condensed matter physics is development and engineering of electronic devices which carrier “bit” informations in the spin degree of freedom of the electronc instead of their charge. This research line is called indeed “spintronics”. … Read the rest

Inhomogeneities in Cuprates

If the mechanism of high-Tc superconductivity is electronic, to understand the electronic excitation spectrum is as important as to understand phonons was important to develop BCS theory. In this regard charge and spin inhomogeneous states, often found in … Read the rest

Unconventional electron-phonon interaction and nonadiabatic effects

The conventional understanding of the electron-phonon phenomenology in condensed matter strongly relies on the adiabatic assumption, i.e. that nuclei dynamics is much slower than the electron one. In solid crystals the validity of this assumption is usually related to the … Read the rest

Topological vs. Metric distance

Basically all existing models of collective animal behaviour (bird flocks, fish schools, etc) assume that the interaction between different individuals depends on the metric distance, just as in physics. This implies, for example, that two birds 5 meters apart … Read the rest

Protein Folding

Protein Folding is a specific chemical and physical transition by which a linear sequence of aminoacids finds its functional (native) three dimensional structure. The theoretical study of protein folding represents perhaps one of the most challenging research with a marked

Read the rest

Home Page of Andrea Cavagna

Education:

Post-Doc, Theoretical Physics, Physics Dept, Manchester University, UK, 2001 (with Alan Bray and Mike Moore)

Post-Doc, Condensed Matter, Theoretical Physics Dept, Oxford University, UK, 1999 (with David Sherrington)

Ph.D. in Theoretical Physics, University of Rome Sapienza, Italy, 1998 … Read the rest

STARFLAG: a project on collective animal behaviour

Collective animal behaviour is a fascinating phenomenon. How does global co-ordination emerge in a flock of thousands starlings swirling at dusk? How does a school of sardines organize in a circular pattern? What is the evolutionary function of collective behaviour? Read the rest

COBBS – Press and Media Coverage

The seventh starling (Murmuration) – The Guardian

Choreografie ohne Choreografen – NZZ

 

Birds of a feather … track seven neighbors to flock together – News at Princeton

How do starlings create those mesmerizing murmurations – Cornell Lab Ornithology

Editorial: Read the rest

Scale-free networks

Scale-Free Networks are present in a wide list of phenomena. Examples range from the structure of the Internet and that of the WWW (we shall see in the following that they are different systems) to the interconnections between financial agents … Read the rest

Transport in binary mixtures

When a binary fluid mixture at the critical concentration is cooled from a high temperature to a sufficiently low temperature (below a critical one), the original homogeneous phase becomes unstable and spontaneously evolves into two phases separated by an interface. … Read the rest

Complexlight

Light and Complexity

Funding Body: ERC Starting Grant (StG), PE2, ERC-2007-StG
(2008-2013) EUR 1085K
Claudio Conti
The project is aimed at funding a multi-disciplinary laboratory on nonlinear optics and photonics in soft-colloidal materials and on “complex lightwave systems”. A team … Read the rest

Lagrangian Turbulence

Recently, part of the research activity on turbulence has focused on temporal properties of turbulent statistics which are much less known than the equivalent spatial properties, and are expected to bring information on some of the mechanisms responsible for intermittency … Read the rest

Scalar Turbulence

The ability of efficiently mixing transported substances is one of the most distinctive properties of turbulence. For instance, it is turbulence (induced by the spoon) that allows cream to rapidly invade a cup of coffee, indeed if only molecular diffusion … Read the rest

Inertial Particles in Turbulent Flows

We already mentioned that enhanced mixing is probably one of the most distinguishing feature of turbulence. When a turbulent flow is seeded with particulate matter having a finite size and/or density different from that of the carrier fluid, new features … Read the rest

La fisica della sabbia a… cena

Read the rest