1,395 research outputs found
Orbit decomposition of Jordan matrix algebras of order three under the automorphism groups
The orbit decomposition is given under the automorphism group on the real
split Jordan algebra of all hermitian matrices of order three corresponding to
any real split composition algebra, or the automorphism group on the
complexification, explicitly, in terms of the cross product of H. Freudenthal
and the characteristic polynomial.Comment: v2, 32 pages, presentation improved, minor errors corrected, and the
title changed as appeared in J. Math. Sci. Univ. Toky
The explanation of the deformed Schild string
The author comments on [1]. One of the deformed actions can express the
Neveu-Schwarz-Ramond superstring under three gauge conditions. One of these
depends on a matrix induced by the string coordinate.Comment: 6 page
Primordial fractal density perturbations and structure formation in the Universe: 1-Dimensional collisionless sheet model
Two-point correlation function of galaxy distribution shows that the
structure in the present Universe is scale-free up to a certain scale (at least
several tens Mpc), which suggests that a fractal structure may exist. If small
primordial density fluctuations have a fractal structure, the present
fractal-like nonlinear structure below the horizon scale could be naturally
explained. We analyze the time evolution of fractal density perturbations in
Einstein-de Sitter universe, and study how the perturbation evolves and what
kind of nonlinear structure will come out. We assume a one-dimensional
collisionless sheet model with initial Cantor-type fractal perturbations. The
nonlinear structure seems to approach some attractor with a unique fractal
dimension, which is independent of the fractal dimensions of initial
perturbations. A discrete self-similarity in the phase space is also found when
the universal nonlinear fractal structure is reached.Comment: 17 pages, 19 jpeg figures. Accepted for publication in ApJ. Figures
are also available from
http://www.phys.waseda.ac.jp/gravity/~tatekawa/0003124/figs.tar.g
Spin Configuration in the 1/3 Magnetization Plateau of Azurite Determined by NMR
High magnetic field Cu NMR spectra were used to determine the local
spin polarization in the 1/3 magnetization plateau of azurite,
Cu(CO)(OH), which is a model system for the distorted diamond
antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the
Cu2 (dimer) sites is found to be field independent, negative and strongly
anisotropic, corresponding to 10 % of fully polarized spin in a
-orbital. This is close to the expected configuration of the "quantum"
plateau, where a singlet state is stabilized on the dimer. However, the
observed non-zero spin polarization points to some triplet admixture, induced
by strong asymmetry of the diamond bonds and .Comment: Phys. Rev. Lett. 102, in press (2009
Statistical Mechanics of Self--Gravitating System : Cluster Expansion Method
We study statistical mechanics of the self--gravitating system applying the
cluster expansion method developed in solid state physics. By summing infinite
series of diagrams, we derive a complex free energy whose imaginary part is
related to the relaxation time of the system. Summation of another series
yields two--point correlation function whose correlation length is essentially
given by the Jeans wavelength of the system.Comment: 4 pages including 2 eps figures, RevTe
Cosmic structures via Bose Einstein condensation and its collapse
We develop our novel model of cosmology based on the Bose-Einstein
condensation. This model unifies the Dark Energy and the Dark Matter, and
predicts multiple collapse of condensation, followed by the final acceleration
regime of cosmic expansion. We first explore the generality of this model,
especially the constraints on the boson mass and condensation conditions. We
further argue the robustness of this model over the wide range of parameters of
mass, self coupling constant and the condensation rate. Then the dynamics of
BEC collapse and the preferred scale of the collapse are studied. Finally, we
describe possible observational tests of our model, especially, the periodicity
of the collapses and the gravitational wave associated with them.Comment: 21 pages, 5 figure
Large-scale mapping observations of the CI(3P1-3P0) and CO(J=3-2) lines toward the Orion A molecular cloud
Large scale mapping observations of the 3P1-3P0 fine structure transition of
atomic carbon (CI, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the
Orion A molecular cloud have been carried out with the Mt. Fuji
submillimeter-wave telescope. The observations cover 9 square degrees, and
include the Orion nebula M42 and the L1641 dark cloud complex. The CI emission
extends over almost the entire region of the Orion A cloud and is surprisingly
similar to that of 13CO(J=1-0).The CO(J=3-2) emission shows a more featureless
and extended distribution than CI.The CI/CO(J=3-2) integrated intensity ratio
shows a spatial gradient running from the north (0.10) to the south (1.2) of
the Orion A cloud, which we interpret as a consequence of the temperature
gradient. On the other hand, the CI/13CO(J=1-0) intensity ratio shows no
systematic gradient. We have found a good correlation between the CI and
13CO(J=1-0) intensities over the Orion A cloud. This result is discussed on the
basis of photodissociation region models.Comment: Text file is 13 pages long, and 3 figure files (pdf format). NRO
Report No. 508 (1999). University of Tokyo, Resceu 41/9
Swarm-Oscillators
Nonlinear coupling between inter- and intra-element dynamics appears as a
collective behaviour of elements. The elements in this paper denote symptoms
such as a bacterium having an internal network of genes and proteins, a
reactive droplet, a neuron in networks, etc. In order to elucidate the
capability of such systems, a simple and reasonable model is derived. This
model exhibits the rich patterns of systems such as cell membrane, cell fusion,
cell growing, cell division, firework, branch, and clustered clusters
(self-organized hierarchical structure, modular network). This model is
extremely simple yet powerful; therefore, it is expected to impact several
disciplines.Comment: 9 pages, 4 figure
Quantum Markov Process on a Lattice
We develop a systematic description of Weyl and Fano operators on a lattice
phase space. Introducing the so-called ghost variable even on an odd lattice,
odd and even lattices can be treated in a symmetric way. The Wigner function is
defined using these operators on the quantum phase space, which can be
interpreted as a spin phase space. If we extend the space with a dichotomic
variable, a positive distribution function can be defined on the new space. It
is shown that there exits a quantum Markov process on the extended space which
describes the time evolution of the distribution function.Comment: Lattice2003(theory
Unambiguous pure state identification without classical knowledge
We study how to unambiguously identify a given quantum pure state with one of
the two reference pure states when no classical knowledge on the reference
states is given but a certain number of copies of each reference quantum state
are presented. By the unambiguous identification, we mean that we are not
allowed to make a mistake but our measurement can produce an inconclusive
result. Assuming the two reference states are independently distributed over
the whole pure state space in a unitary invariant way, we determine the optimal
mean success probability for an arbitrary number of copies of the reference
states and a general dimension of the state space. It is explicitly shown that
the obtained optimal mean success probability asymptotically approaches that of
the unambiguous discrimination as the number of the copies of the reference
states increases.Comment: v3: 8 pages, minor corrections, journal versio
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