12,625 research outputs found
Critical Behavior of J/psi across the Phase Transition from QCD sum rules
We study behavior of J/psi in hot gluonic matter using
QCD sum rules. Taking into account temperature dependences of the gluon
condensates extracted from lattice thermodynamics for the pure SU(3) system, we
find that the mass and width of J/psi exhibit rapid change across the critical
temperature.Comment: 5 pages, 3 figures. Poster contribution for Quark Matter 2008. To be
published in the proceeding
Cluster Variation Approach to the Random-Anisotropy Blume-Emery-Griffiths Model
The random--anisotropy Blume--Emery--Griffiths model, which has been proposed
to describe the critical behavior of He--He mixtures in a porous
medium, is studied in the pair approximation of the cluster variation method
extended to disordered systems. Several new features, with respect to mean
field theory, are found, including a rich ground state, a nonzero percolation
threshold, a reentrant coexistence curve and a miscibility gap on the high
He concentration side down to zero temperature. Furthermore, nearest
neighbor correlations are introduced in the random distribution of the
anisotropy, which are shown to be responsible for the raising of the critical
temperature with respect to the pure and uncorrelated random cases and
contribute to the detachment of the coexistence curve from the line.Comment: 14 pages (plain TeX) + 12 figures (PostScript, appended), Preprint
POLFIS-TH.02/9
A density functional theory for general hard-core lattice gases
We put forward a general procedure to obtain an approximate free energy
density functional for any hard-core lattice gas, regardless of the shape of
the particles, the underlying lattice or the dimension of the system. The
procedure is conceptually very simple and recovers effortlessly previous
results for some particular systems. Also, the obtained density functionals
belong to the class of fundamental measure functionals and, therefore, are
always consistent through dimensional reduction. We discuss possible extensions
of this method to account for attractive lattice models.Comment: 4 pages, 1 eps figure, uses RevTeX
Relative information entropy of an inhomogeneous universe
In the context of averaging an inhomogeneous cosmological model, we propose a
natural measure identical to the Kullback-Leibler relative information entropy,
which expresses the distinguishability of the local inhomogeneous density field
from its spatial average on arbitrary compact domains. This measure is expected
to be an increasing function in time and thus to play a significant role in
studying gravitational entropy. To verify this conjecture, we explore the time
evolution of the measure using the linear perturbation theory of a spatially
flat FLRW model and a spherically symmetric nonlinear solution. We discuss the
generality and conditions for the time-increasing nature of the measure, and
also the connection to the backreaction effect caused by inhomogeneities.Comment: 9 pages, 4 figures, LaTeX 2e using aipproc.cls, published in AIP
Conf. Proc., minor corrections mad
Bending and springback prediction method based on multi-scale finite element analyses for high bendability and low springback sheet generation
In this study, a sheet bendability and springback property evaluation technology through bending test simulations is newly developed using our multi-scale finite element analysis code, which is based on the crystallographic homogenization method
Quantum Phase Transitions to Charge Order and Wigner Crystal Under Interplay of Lattice Commensurability and Long-Range Coulomb Interaction
Relationship among Wigner crystal, charge order and Mott insulator is studied
by the path-integral renormalization group method for two-dimensional lattices
with long-range Coulomb interaction. In contrast to Hartree-Fock results, the
solid stability drastically increases with lattice commensurability. The
transition to liquid occurs at the electron gas parameter for the
filling showing large reduction from in the continuum
limit. Correct account of quantum fluctuations are crucial to understand
charge-order stability generally observed only at simple fractional fillings
and nature of quantum liquids away from them.Comment: 4 pages including 7 figure
Information Entropy in Cosmology
The effective evolution of an inhomogeneous cosmological model may be
described in terms of spatially averaged variables. We point out that in this
context, quite naturally, a measure arises which is identical to a fluid model
of the `Kullback-Leibler Relative Information Entropy', expressing the
distinguishability of the local inhomogeneous mass density field from its
spatial average on arbitrary compact domains. We discuss the time-evolution of
`effective information' and explore some implications. We conjecture that the
information content of the Universe -- measured by Relative Information Entropy
of a cosmological model containing dust matter -- is increasing.Comment: LateX, PRLstyle, 4 pages; to appear in PR
Exact Ground-State Energy of the Ising Spin Glass on Strips
We propose a new method for exact analytical calculation of the ground-state
energy of the Ising spin glass on strips. An outstanding advantage of this
method over the numerical transfer matrix technique is that the energy is
obtained for complex values of the probability describing quenched randomness.
We study the and the site-random models using this method for strips of
various sizes up to . The ground-state energy of these models is
found to have singular points in the complex-probability plane, reminiscent of
Lee-Yang zeros in the complex-field plane for the Ising ferromagnet. The Ising model has a series of singularities which may approach a limiting
point around on the real axis in the limit of infinite width.Comment: 10 pages, 12 Postscript figures, LaTeX, uses subeqn.sty, minor
changes in tex-fil
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