1,451 research outputs found
Generating functional analysis of complex formation and dissociation in large protein interaction networks
We analyze large systems of interacting proteins, using techniques from the
non-equilibrium statistical mechanics of disordered many-particle systems.
Apart from protein production and removal, the most relevant microscopic
processes in the proteome are complex formation and dissociation, and the
microscopic degrees of freedom are the evolving concentrations of unbound
proteins (in multiple post-translational states) and of protein complexes. Here
we only include dimer-complexes, for mathematical simplicity, and we draw the
network that describes which proteins are reaction partners from an ensemble of
random graphs with an arbitrary degree distribution. We show how generating
functional analysis methods can be used successfully to derive closed equations
for dynamical order parameters, representing an exact macroscopic description
of the complex formation and dissociation dynamics in the infinite system
limit. We end this paper with a discussion of the possible routes towards
solving the nontrivial order parameter equations, either exactly (in specific
limits) or approximately.Comment: 14 pages, to be published in Proc of IW-SMI-2009 in Kyoto (Journal of
Phys Conference Series
Neutrino Mixing Predictions of a Minimal SO(10) Model with Suppressed Proton Decay
During the past year, a minimal renormalizable supersymmetric SO(10) model
has been proposed with the following properties: it predicts a naturally stable
dark matter and neutrino mixing angles theta_atm and theta_13 while at the same
time accommodating CKM CP violation among quarks with no SUSY CP problem.
Suppression of proton decay for all allowed values of tan beta strongly
restricts the flavor structure of the model making it predictive for other
processes as well. We discuss the following predictions of the model in this
paper, e.g. down-type quark masses, and neutrino oscillation parameters, U_e3,
delta_MNSP, which will be tested by long baseline experiments such as T2K and
subsequent experiments using the neutrino beam from JPARC. We also calculate
lepton flavor violation and the lepton asymmetry of the Universe in this model.Comment: 22 pages, 11 figure
Suppressing Proton Decay in the Minimal SO(10) Model
We show that in a class of minimal supersymmetric SO(10) models which have
been found to be quite successful in predicting neutrino mixings, all proton
decay modes can be suppressed by a particular choice of Yukawa textures. This
suppression works for contributions from both left and right operators for
nucleon decay and for arbitrary \tan\beta. The required texture not only fits
all lepton and quark masses as well as CKM parameters but it also predicts
neutrino mixing parameter U_e3 and Dirac CP phase \sin|\delta_MNS| to be
0.07-0.09 and 0.3-0.7 respectively. We also discuss the relation between the
GUT symmetry breaking parameters for the origin of these textures.Comment: 7 pages, 2 figure
Parallel dynamics of continuous Hopfield model revisited
We have applied the generating functional analysis (GFA) to the continuous
Hopfield model. We have also confirmed that the GFA predictions in some typical
cases exhibit good consistency with computer simulation results. When a
retarded self-interaction term is omitted, the GFA result becomes identical to
that obtained using the statistical neurodynamics as well as the case of the
sequential binary Hopfield model.Comment: 4 pages, 2 figure
Symmetric sequence processing in a recurrent neural network model with a synchronous dynamics
The synchronous dynamics and the stationary states of a recurrent attractor
neural network model with competing synapses between symmetric sequence
processing and Hebbian pattern reconstruction is studied in this work allowing
for the presence of a self-interaction for each unit. Phase diagrams of
stationary states are obtained exhibiting phases of retrieval, symmetric and
period-two cyclic states as well as correlated and frozen-in states, in the
absence of noise. The frozen-in states are destabilised by synaptic noise and
well separated regions of correlated and cyclic states are obtained. Excitatory
or inhibitory self-interactions yield enlarged phases of fixed-point or cyclic
behaviour.Comment: Accepted for publication in Journal of Physics A: Mathematical and
Theoretica
Dynamical replica theoretic analysis of CDMA detection dynamics
We investigate the detection dynamics of the Gibbs sampler for code-division
multiple access (CDMA) multiuser detection. Our approach is based upon
dynamical replica theory which allows an analytic approximation to the
dynamics. We use this tool to investigate the basins of attraction when phase
coexistence occurs and examine its efficacy via comparison with Monte Carlo
simulations.Comment: 18 pages, 2 figure
Gauge Symmetry Breaking through Soft Masses in Supersymmetric Gauge Theories
Effects of soft breaking in N=1 supersymmetric gauge theories are studied.
For N_f < N_c, we include the dynamics of the non-perturbative superpotential
and use the original (s)quark and gauge fields. For N_f > N_c +1, we formulate
the dynamics in terms of dual (s)quarks and a dual gauge group SU(N_f-N_c). The
mass squared of the squarks can be negative triggering spontaneous breakdown of
flavor and color symmetry. The general condition for stability of the vacuum is
derived. We determine the breaking pattern, determine the spectrum and argue
that the masses vary smoothly as one crosses from the Higgs phase into the
confining phase, thus exhibiting complementarity.Comment: Contribution to Inauguration Conferference of Asia Pacific Center for
Theoretical Physics, 4-10 June, 1996, Seoul National University; LaTeX, no
macros neede
Proton decay and μ → e + γ connection in a renormalizable SO(10) GUT for neutrinos
Supersymmetric SO(10) grand unified models with renormalizable Yukawa
couplings involving {\bf 10}, {\bf 126} and {\bf 120} Higgs fields have been
shown to give a very economical theory for understanding quark-lepton flavor in
a unified framework. In previous papers, we showed how nucleon decay can be
suppressed in these models without invoking cancellation, by choice of Yukawa
flavor texture within a type II seesaw framework for neutrinos that explains
all mixings and masses including the recently observed "large" .
In this follow-up paper, we extend our earlier work to the case of type I
seesaw and show that the recently measured "large" can be
accommodated in this case while suppressing proton decay. We then point out
that the two cases (type I and II) lead to different testable predictions for
and as well as different
flavor final states in nucleon decay. In particular, we find that for the type
I seesaw case, can be observable while at the same
time suppressing , whereas in the type II seesaw case,
is always suppressed whereas is
observable.Comment: 27 pages, 2 figure
Belief Propagation for Error Correcting Codes and Lossy Compression Using Multilayer Perceptrons
The belief propagation (BP) based algorithm is investigated as a potential
decoder for both of error correcting codes and lossy compression, which are
based on non-monotonic tree-like multilayer perceptron encoders. We discuss
that whether the BP can give practical algorithms or not in these schemes. The
BP implementations in those kind of fully connected networks unfortunately
shows strong limitation, while the theoretical results seems a bit promising.
Instead, it reveals it might have a rich and complex structure of the solution
space via the BP-based algorithms.Comment: 18 pages, 18 figure
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