13,610 research outputs found
Leptogenesis in a Hybrid Texture Neutrino Mass Model
We investigate the CP asymmetry for a hybrid texture of the neutrino mass
matrix predicted by family symmetry in the context of the type-I seesaw
mechanism and examine its consequences for leptogenesis. We, also, calculate
the resulting Baryon Asymmetry of the Universe (BAU) for this texture.Comment: Accepted for publication in Mod. Phys. Lett.
Thermodynamic Irreversibility from high-dimensional Hamiltonian Chaos
This paper discusses the thermodynamic irreversibility realized in
high-dimensional Hamiltonian systems with a time-dependent parameter. A new
quantity, the irreversible information loss, is defined from the Lyapunov
analysis so as to characterize the thermodynamic irreversibility. It is proved
that this new quantity satisfies an inequality associated with the second law
of thermodynamics. Based on the assumption that these systems possess the
mixing property and certain large deviation properties in the thermodynamic
limit, it is argued reasonably that the most probable value of the irreversible
information loss is equal to the change of the Boltzmann entropy in statistical
mechanics, and that it is always a non-negative value. The consistency of our
argument is confirmed by numerical experiments with the aid of the definition
of a quantity we refer to as the excess information loss.Comment: LaTeX 43 pages (using ptptex macros) with 11 figure
Spontaneous structure formation in a network of chaotic units with variable connection strengths
As a model of temporally evolving networks, we consider a globally coupled
logistic map with variable connection weights. The model exhibits
self-organization of network structure, reflected by the collective behavior of
units. Structural order emerges even without any inter-unit synchronization of
dynamics. Within this structure, units spontaneously separate into two groups
whose distinguishing feature is that the first group possesses many
outwardly-directed connections to the second group, while the second group
possesses only few outwardly-directed connections to the first. The relevance
of the results to structure formation in neural networks is briefly discussed.Comment: 4 pages, 3 figures, REVTe
Origin of complexity in multicellular organisms
Through extensive studies of dynamical system modeling cellular growth and
reproduction, we find evidence that complexity arises in multicellular
organisms naturally through evolution. Without any elaborate control mechanism,
these systems can exhibit complex pattern formation with spontaneous cell
differentiation. Such systems employ a `cooperative' use of resources and
maintain a larger growth speed than simple cell systems, which exist in a
homogeneous state and behave 'selfishly'. The relevance of the diversity of
chemicals and reaction dynamics to the growth of a multicellular organism is
demonstrated. Chaotic biochemical dynamics are found to provide the
multi-potency of stem cells.Comment: 6 pages, 2 figures, Physical Review Letters, 84, 6130, (2000
Self-organized and driven phase synchronization in coupled maps
We study the phase synchronization and cluster formation in coupled maps on
different networks. We identify two different mechanisms of cluster formation;
(a) {\it Self-organized} phase synchronization which leads to clusters with
dominant intra-cluster couplings and (b) {\it driven} phase synchronization
which leads to clusters with dominant inter-cluster couplings. In the novel
driven synchronization the nodes of one cluster are driven by those of the
others. We also discuss the dynamical origin of these two mechanisms for small
networks with two and three nodes.Comment: 4 pages including 2 figure
WILLINGNESS TO PAY FOR NON-GENETICALLY MODIFIED FOOD: EVIDENCE OF HYPOTHETICAL BIAS FROM AN AUCTION EXPERIMENT IN JAPAN
Replaced with revised version of paper 08/05/04.Consumer/Household Economics,
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