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Written by Andrea Cavagna   
Wednesday, 27 February 2008 18:24

 


I was trained as a theoretical physicist and I have worked mainly in statistical mechanics of disordered systems, with particular emphasis on spin-glasses, structural glasses and supercooled liquids. I while ago I also did some work in multi-agents modelling (econophysics).

More recently, I started working on collective animal behaviour, trying to adopt an interdisciplinary approach that uses methods from statistical physics to solve biological and ethological problems. In this second life of mine, I mainly work on collecting and analyzing empirical data about bird flocks and (in the near future) insect swarms. Being a theoretician, this is fun, and the results are not as bad as one may suppose.

I belong to the Unit of Statistical Mechanics and Complexity (SMC), of the Institute for Complex Systems (ISC-CNR). I am also associated to the Department of Physics at the University La Sapienza.


COLLECTIVE ANIMAL BEHAVIOUR:

From 2006 to 2008 I was the coordinator of the INFM-CNR node of the EC-funded STARFLAG project. The aim of my node was to collect three-dimensional data of free flying starlings in very large flocks and to understand the fundamental rules of interaction among the birds. Once we had the 3D data we finally discovered that the interaction is quite different from what was assumed in most models of collective behaviour. The new interaction we discovered is the key ingredient granting the extraordinary cohesion that we see in nature.
This project was done in collaboration with Irene Giardina, Giorgio Parisi and many others. Read more by visiting the page of the STARFLAG project.
 
As a natural development of STARFLAG we will soon start a new project, ART-SWARM, coordinated by Irene Giardina and financed by the Italian Institute of Technology (IIT). ART-SWARM will focus on the collective behaviour of insect swarms, in particular midges. We are currently filling several positions, both at the post-doctoral and at the diploma level. If you are interested contact me! ART-SWARM is about to begin...
 

SUPERCOOLED LIQUIDS AND THE GLASS TRANSITION:

The amorphous excitations in a deeply supercooled liquid

I am working on devising new methods to detect a growing static correlation length in deeply supercooled liquids. By using amorphuos boundary conditions we measured for the first time a thermodynamic correlation length. In so doing we test the validity of different theoretical frameworks of the glass transition, namely the Adam-Gibbs theory and the Mosaic (aka Random First Order) theory. We are also trying to measure the surface tension between different amorphous phases in deeply supercooled liquids and to establish a link between static relaxation and dynamic heterogeneities through the concept of surface tension. My coworkers on this topic are Paolo Verrocchio, Tomas Grigera, Chiara Cammarota, Giacomo Gradenigo, Giulio Biroli and Jean-Philippe Bouchaud.

Left: we created a spherical excitation in a supercooled liquid and let the particles relax. Light=large displacements, dark=small displacement. Upper panels: high temperature; lower panels: low temperature.

 

 

Recent Glassy Publications:
 
A novel method for evaluating the critical nucleus and the surface tension in systems with first order phase transition
C. Cammarota, A. Cavagna
Journal of Chemical Physics 127, 214703 (2007)

Mosaic Multistate Scenario Versus One-State Description of Supercooled Liquids
A. Cavagna, T. S. Grigera and P. Verrocchio
Physical Review Letters 98, 187801 (2007)

Thermodynamic signature of growing amorphous order in glass-forming liquids
G. Biroli, J.-P. Bouchaud, A. Cavagna, T. S. Grigera, P. Verrocchio
Nature Physics 4, 771 - 775 (01 Oct 2008)
 
Surface tension fluctuations and a new spinodal point in glass-forming liquids
C. Cammarota, A. Cavagna, G. Gradenigo, T.S. Grigera, P. Verrocchio
 
Numerical determination of the exponents controlling the relationship between time, length and temperature in glass-forming liquids
C. Cammarota, A. Cavagna, G. Gradenigo, T.S. Grigera, P. Verrocchio
 
A phase-separation perspective on dynamic heterogeneities in glass-forming liquids
C. Cammarota, A. Cavagna, I. Giardina, G. Gradenigo, T. S. Grigera, G. Parisi, P. Verrocchio

Read more about the growth of amorphous order in glass-forming liquids.

 

A BROADER PERSPECTIVE:

I have been working on several other topics in the past, and I still do. Statistical physics is my original field of expertise, and in particular disordered systems and glasses. Check the tags below to get a broader idea of my research and my collaborations trough some selected publications:

 

PUBLICATIONS AND CV:

My publications ordered according to the number of citations by Google Scholar

My publications ordered cronologically by the Arxiv

My publications ordered in a CiteULike library

You can find a very brief CV here.

 

CURRENT POSTDOCS:

Massimiliano Viale, collective animal behaviour, inverse problem (STARFLAG)


CURRENT STUDENTS:

  • Edmondo Silvestri (Diploma): collective animal behaviour, models running on GPU (STARFLAG)
  • Raffaele Tavarone (Diploma): collective animal behaviour, inter-individual interaction (STARFLAG)


FORMER STUDENTS:

  • Chiara Cammarota (Diploma and PhD): glasses, surface tension in amorphous systems, growth of amorphous order, mosaic theory (now a post-doc at CEA, in Saclay)
  • Alessio Cimarelli (Diploma): collective animal behaviour: velocity field (STARFLAG)
  • Valentino Pompili (Diploma): collective animal behaviour, diffusion properties (STARFLAG)
  • Fabio Stefanini (Diploma): STARFLAG (now a PhD student at the Institute of Neuroinformatics, ETH, Zurich)
  • Alessandro Attanasi (Diploma and PhD): elastic effects in supercooled liquids, effects of quenched disorder in superconductors (now employed at NERGAL)
  • Andrea Procaccini (PhD): STARFLAG (now a post-doc in the Statistical Physics and Computational Systems Biology group at ISI, Torino)
  • Alessia Annibale (Diploma): Spin Glasses (now a Lecturer in the Disordered Systems group at King's College, London)
  • Elisa Trevigne (Diploma): Spin Glasses (now at University Tor Vergata, Rome)
  • Giulia Gualdi (Diploma): Spin Glasses (now at University of Camerino)

PEDESTRIAN REVIEWS:

Check my pedagogical reviews on spin-glasses and supercooled liquids, the infamous Spin-Glass Theory for Pedestrians
and Supercooled Liquids for Pedestrians.

 

TEACHING:

I teach a 20hrs course on Disordered Systems for the PhD in Physics at the University `La Sapienza'.

 

CONTACT DETAILS:

Dr Andrea Cavagna
ISC - CNR
Via dei Taurini 19
00185 Rome
Italy
tel: +39 06 4993 7460
fax: +39 06 4993 7440
email: andrea --dot-- cavagna --at-- gmail --dot-- com

 

MONGIBELLO:

This is it, the Mongibello.

 

Last Updated ( Thursday, 25 February 2010 13:29 )