************************************************************* ************************************************************* 2005 09 05 - MONDAY 9.15 - 9.30 OPENING CHAIR: Peter Young 9.30 - 10.10 P. Contucci - The Ghirlanda-Guerra Identities 10.15 - 10.55 H. Nishimori - Existence proof of duality relations in spin glass models 11.00 - 11.30 COFFEE BREAK 11.30 - 12.10 G. Gallavotti - Divergent series sum rules and resonances in classical mechanics 12.15 - 12.55 Y. Ozeki - Gauge theory for gauge glass systems 13.00 - 15.00 LUNCH CHAIR: Nicolas Sourlas 15.00 - 16.00 SHORT TALKS: Mongillo, Takeda, Lukic. 16.00 - 16.30 COFFEE BREAK 16.30 - 16.55 D. Sherrington - Zero Temperature Replica Symmetry Breaking in the Sherrington-Kirkpatrick and Fermionic Ising Spin Glasses; Renormalization Group in RSB Space 17.00 - 17.40 F. Guerra - Fluctuations and overlap locking in mean field spin glass theory 17.45 - 18.25 H. Kitatani - The energy distribution function of finite-dimensional Ising spin glass 18.30 - 19.30 POSTER SESSION ************************************************************* ************************************************************* 2005 09 06 - TUESDAY CHAIR: Federico Ricci-Tersenghi 9.30 - 10.10 J.-P. Bouchaud - Financial markets: the Bachelier-Einstein's legacy 10.15 - 10.55 Y. Kabashima - Application of survey propagation to CDMA multiuser detection 11.00 - 11.30 COFFEE BREAK CHAIR: Miguel Virasoro 11.30 - 12.10 K. Tanaka - Graphical model and generalized belief propagation in probabilistic image processing 12.15 - 12.40 G. Careri - Proton glass of hydrogenated protein powder 12.45 - 13.10 I. Kanter - Asymptotics of the entropy rate for a hidden Markov process 13.15 - 15.00 LUNCH CHAIR: Irene Giardina 15.00 - 16.00 SHORT TALKS: Sasamoto, de Martino, Semerjan. 16.00 - 16.30 COFFEE BREAK 16.30 - 17.10 M. Mezard - Clustering of solutions in constraint satisfaction problems 17.15 - 17.55 A. Montanari - How to prove convergence for belief propagation and related algorithms: a survey 18.00 - 18.40 J. Inoue - Quantum phase transition and decoding performance in Sourlas codes 18.45 - 19.45 POSTER SESSION ************************************************************* ************************************************************* 2005 09 08 - THURSDAY CHAIR: Andrea Cavagna 9.30 - 10.10 M. Weigt - Complex regulatory control in Boolean networks 10.15 - 10.55 H. Yoshino - Fluctuations in spin glasses and some simple domain growth systems 11.00 - 11.30 COFFEE BREAK CHAIR: Scott Kirkpatrick 11.30 - 12.10 G. Biroli - Jamming transitions: glasses, granular media and simple lattice models 12.15 - 12.55 H. Takayama - Glassy Dynamics of Ising Spin Glasses in a Magnetic Field --- Numerical and Real Experiments -- 13.00 - 15.00 LUNCH CHAIR: Enzo Marinari 15.00 - 15.40 SHORT TALKS: Zamponi, Maiorano 15.40 - 16.05 G. Parisi - On the complexity in spin glasses 16.10 - 16.40 COFFEE BREAK 16.40 - 17.00 SHORT TALKS: Leuzzi 17.00 - 17.40 M. Moore - Validity of perturbation theory for finite-dimensional spin glasses 17.45 - 18.10 S. Franz - Metastable states, relaxation times and free-energy barriers in finite dimensional glassy systems 18.15 - 18.30 CLOSING SHORT TALKS ARE 17' + 3' for questions each. ******************************************************************* ******************************************************************* ABSTRACTS P. Contucci - The Ghirlanda-Guerra Identities We will show a proof of the Ghirlanda-Guerra identities which only requires that the variance of the Hamiltonian grows like the volume (thermodynamic stability). Our result is expressed in terms of the model's covariance and applies to all known spin glass models. S. Franz - Metastable States, Relaxation Times and Free-energy Barriers in Finite Dimensional Glassy Systems A prominent theoretical problem in the physics of glassy systems is the comprehension of the nature of the relaxation processes that restore ergodicity in regions where approximated liquid theories or Mean-Field models predict a spurious structural arrest. These processes have a non-perturbative nature and a satisfactory theory is not available at present. In this talk I will deal with spin glass models with long-but-finite Kac interactions which offers the opportunity of attacking the problem in asymptotic expansions around mean field. I will first show how to define metastable states, then argue that they dominate the low temperature dynamics and finally relate the equilibrium relaxation time to free-energy barriers computable in principle in a purely static setting. Being the essence of the argument based on time scale separation, I will discuss its relevance for glassy materials. F. Guerra - Fluctuations and overlap locking in mean field spin glass theory In the frame of the interpolation methods developed in recent years, we consider the phenomenon of overlap locking by the action of a suitably chosen auxiliary system on the original mean field spin glass system. Overlap locking is ruled by a fluctuation parameter, in the infinite volume limit. As a simple application, we show how the replica symmetric solution is valid up to the expected Almeida-Thouless line. Moreover, we show how the Derrida - Ruelle - Parisi probability cascades, originating from the generalized random energy model, are able to provide overlap locking on the Sherrington-Kirkpatrick spin glass. I. Kanter - Asymptotics of the Entropy Rate for a Hidden Markov Process We calculate the Shannon entropy rate of a binary Hidden Markov Process (HMP), of given transition rate and noise epsilon (emission), as a series expansion in epsilon. We map the problem onto a one-dimensional Ising model in a large field of random signs and calculate the expansion coefficients up to second order in epsilon. For finite histories, Cover's upper bounds is also calculated. Surprisingly, we find that for a fixed order k and history of n steps, the bounds become independent of n for large enough n. This observation is the basis of a conjecture, that the upper bound obtained for n >= (k+3)/2 gives the exact entropy rate for any desired order k of epsilon. A. Montanari - How to prove convergence for belief propagation and related algorithms: a survey. There exist a few techniques for proving convergence of belief propagation algorithms. I will review them and explain a few applications to statistical physics and beyond. I will then stress the importance of developing more general tools. D. Sherrington - Zero Temperature Replica Symmetry Breaking in the Sherrington-Kirkpatrick and Fermionic Ising Spin Glasses; Renormalization Group in RSB Space By means of accurate numerical self-consistent solutions of replica symmetry breaking (RSB) up to fifth order for the SK-model, coupled with analogies to Wilson's renormalization group but with the number of replica symmetry breaking steps playing a role analogous to that of decimation scales, we report evidence for a non-trivial zero-temperature limit of the Parisi order function q(x). The zero-temperature limiting order function exhibits an error function form with a characteristic correlation length in replica space which is also the solution of an effective one-dimensional `field theory'. We also report investigations of the zero-temperature local magnetic field distribution which again show RG behaviour in RSB space, as well as the now-expected pseudogap but also evidence for two different limiting slopes for in the low field limit. The fermionic Ising spin glass shows similar behaviour, with the local field distribution reflected in the single-particle spectral function. H. Takayama - Glassy Dynamics of Ising Spin Glasses in a Magnetic Field --- Numerical and Real Experiments -- Numerical experiments (standard MC simulations) on two aging protocols of the 3D Ising EA spin-glass (SG) in a static magnetic field $h$ are carried out and are compared with the corresponding experiments on real SG materials. One is the field-shift aging protocol at temperature $T$ with waiting time $\tw$ before $h$ is switched on [1]. Extracting the dynamical crossover time, $\tcr(T; \tw, h)$ and introducing properly the two characteristic length scales associated with $\tcr$ and $\tw$, we have found an interesting scaling between the latter two which are normalized by the static field crossover length introduced in the SG droplet theory. The result implies the instability of the SG phase in the equilibrium limit even under an infinitesimal $h$. Also, the extracted dynamical crossover, when it is extrapolated to the time rage of real experiments, coincides even semi-quantitatively with the occurrence of irreversibility of the zero-field-cooled magnetization (ZFCM) and the field-cooled magnetization (FCM). We have also studied the FCM process under relatively small $h$ in detail and have compared with the corresponding experimental results [2]. Both numerical and real experimental results are explained by means of the droplet picture in a unified way. Particularly, the cusp-like behavior of the FCM (not only ZFCM) is interpreted as evidence for a `thermal blocking' transition frequently observed in glassy systems. [1] H. Takayama and K. Hukushima: J. Phys. Soc. Jpn. 73 (2004) 2077. [2] P.E. J\"onsson and H. Takayama: J. Phys. Soc. Jpn. 74 (2005) 1131.