David Sherrington
(Rudolf Peierls Centre for Theoretical Physics, University of Oxford, UK)
11/06/2014, 10:00
In 1979 John Hertz introduced the concept of the Stoner
Glass to describe spin glass ordering in itinerant
transition metal magnetic alloys.
Two decades earlier an interesting behaviour (of distinctly
frequency-dependent but sharpish peaks in the dynamical
permittivity) was observed in some ceramic ionic alloys, now
known as relaxor ferroelectrics. They have received a great
deal of...
Heinz Horner
(Inst. für Theor. Physik, University of Heidelberg)
11/06/2014, 11:00
Time-reparametrization-invariance has been discussed in the
context of glasses as well as different models of spin glasses.
In particular I have investigated this question within the
framework of the spherical p-spin-glass-model, since in this
model at least the equations of motion can be written down
in a closed form. They are closely related to the mode
coupling approach for glasses....
Nicolas Sourlas
(Ecole Normale Superieure, Paris)
11/06/2014, 13:00
New numerical simulations of the random field Ising model at
zero temperature have been performed recently. I will
review the results of these simulations which add new
hindsight to the nature of the phase transition in this model.
Reimer Kuhn
(Kings College, London)
11/06/2014, 14:30
We compute spectra of large random stochastic matrices,
i.e. Markov matrices defined on random graphs, where each
edge (ij) in a (sparse) random graph is given a positive
random weight W_{ij}>0 in such a fashion that the each
column sum of the matrix W is normalized to one,
\sum_i W_{ij}= 1. We use the replica method to compute
spectra in the thermodynamic limit, and the cavity...
Theo Nieuwenhuizen
(University of Amsterdam, The Netherlands)
11/06/2014, 15:30
Stochastic electrodynamics assumes a classical world in a
background of stochastic electromagnetic fields having the
zero-point Planck energy $\hbar\omega/2$ per mode. The
theory explains various linear problems, such as harmonic
oscillators and the Casimir effect. Under certain
assumptions, the Heisenberg and Schrodinger equations have
been derived. Likewise, entanglement has been...
David Saad
(Aston University, Birmingham, UK)
12/06/2014, 10:00
The dynamics of non-equilibrium Ising model with parallel
updates is investigated using a generalized mean field
approximation that incorporates multiple two-site
correlations at any two time steps, which can be obtained
recursively. The proposed method shows significant
improvement in predicting local system properties compared
to other mean field approximation techniques,...
Guido Sanguinetti
(University of Edinburg)
12/06/2014, 11:15
Stochastic processes are widely used mathematical models in
disciplines ranging from biology to physics and economics.
Consequently, there has been considerable interest in the
statistics and machine learning communities in devising
approximate Bayesian inference methods for specific classes
of stochastic processes. The general scenario considered is
that the data consists of noisy...
Ramon Grima
(University of Edinburg)
12/06/2014, 13:45
Exact solutions of the chemical master equation are only
known for a handful of simple chemical systems. In the past
decade, the linear-noise approximation (LNA) has become a
popular means to systematically approximate the master
equation and to hence obtain insight into the effect of
noise on the dynamics of biochemical systems. However a
number of assumptions underlying the LNA...
Bert Kappen
(University of Nijmegen, The Netherlands)
12/06/2014, 15:15
Intelligent systems, whether natural or artificial, must act
in a world that is highly unpredictable. To plan actions
with uncertainty is a stochastic optimal control problem.
However, there are two fundamental problems: the optimal
control solution is intractable to compute and intractable
to represent due the non-trivial state dependence of the
optimal control. This has prevented large...
Enzo Marinari
(Universita di Roma, La Sapienza, Rome)
12/06/2014, 16:15
New experimental results on bacterial growth inspire a novel
top-down approach to study cell metabolism, combining flux
balance and proteomics constraints. Flux Balance Analysis
has been proven a very useful tool in modeling cellular
metabolism, but it is unable to capture features such as the
switch to anaerobic metabolism at high growth rates observed
in bacteria. We introduce the...
Federico RICCI-TERSENGHI
(Universita di Roma, La Sapienza, Roma)
13/06/2014, 10:00
A long standing problem in neuroscience, both in modeling
and in data analysis, is the one of inferring synaptic
couplings from correlations of the sampled neural
activities. The recent availability of techniques allowing
simultaneous recording from several tens electrodes,
in-vitro as well as in-vivo, gave new momentum to research
in this direction. In particular, much effort has...
Giorgio Parisi
(Universita di Roma, La Sapienza, Rome)
13/06/2014, 11:45
In this talk I will describe line phase transitions in the
dynamics of disordered systems. I will elucidate the
relations between the fate of this transition at low
temperature and the equilibrium properties of the system. As
an example I will discuss standard mean field models, as the
p-spin models, and new realistic mean field models as the
Mari-Kurchan model for hard spheres.
Ole Winther
(DTU, Copenhagen)
13/06/2014, 14:00
Expectation Propagation (EP) provides a framework for
approximate inference closely related to the TAP equations.
When the model under consideration is over a latent Gaussian
field, with the approximation being Gaussian, we show how
these approximations can systematically be corrected. A
perturbative expansion is made of the exact but intractable
correction, and can be applied to the...