55,362 research outputs found
Monopole Condensation in Lattice SU(2) QCD
This is the short review of Monte-Carlo studies of quark confinement in
lattice QCD. After abelian projections both in the maximally abelian and
Polyakov gauges, it is seen that the monopole part alone is responsible for
confinement. A block spin transformation on the dual lattice suggests that
lattice QCD is always ( for all ) in the monopole condensed
phase and so in the confinement phase in the infinite volume limit.Comment: Contribution to Confinement '95, March 1995, Osaka, Japan. Names of
figure files are corrected. 8 page uuencoded latex file and 10 ps figure
On the perfect lattice actions of abelian-projected SU(2) QCD
We study the perfect lattice actions of abelian-projected SU(2) gluodynamics.
Using the BKT and duality transformations on the lattice, an effective string
model is derived from the direction-dependent quadratic monopole action,
obtained numerically from SU(2) gluodynamics in maximally abelian gauge. The
string tension and the restoration of continuum rotational invariance are
investigated using strong coupling expansion of lattice string model
analytically. We also found that the block spin transformation can be performed
analytically for the quadratic monopole action.Comment: 3 pages, Latex, 1 figures; talk presented at LATTICE9
Slow quench dynamics of the Kitaev model: anisotropic critical point and effect of disorder
We study the non-equilibrium slow dynamics for the Kitaev model both in the
presence and the absence of disorder. For the case without disorder, we
demonstrate, via an exact solution, that the model provides an example of a
system with an anisotropic critical point and exhibits unusual scaling of
defect density and residual energy for a slow linear quench. We provide
a general expression for the scaling of () generated during a slow
power-law dynamics, characterized by a rate and exponent ,
from a gapped phase to an anisotropic quantum critical point in dimensions,
for which the energy gap for momentum
components () and for the rest components
() with : ().
These general expressions reproduce both the corresponding results for the
Kitaev model as a special case for and and the well-known
scaling laws of and for isotropic critical points for . We also
present an exact computation of all non-zero, independent, multispin
correlation functions of the Kitaev model for such a quench and discuss their
spatial dependence. For the disordered Kitaev model, where the disorder is
introduced via random choice of the link variables in the model's
Fermionic representation, we find that and () for a slow linear quench ending in the gapless
(gapped) phase. We provide a qualitative explanation of such scaling.Comment: 10 pages, 11 Figs. v
Lattice monopole action in pure SU(3) QCD
We obtain an almost perfect monopole action numerically after abelian
projection in pure SU(3) lattice QCD. Performing block-spin transformations on
the dual lattice, the action fixed depends only on a physical scale b. Monopole
condensation occurs for large b region. The numerical results show that
two-point monopole interactions are dominant for large b. We next perform the
block-spin transformation analytically in a simplified case of two-point
monopole interactions with a Wilson loop on the fine lattice. The perfect
operator evaluating the static quark potential on the coarse b-lattice are
derived. The monopole partition function can be transformed into that of the
string model. The static potential and the string tension are estimated in the
string model framework. The rotational invariance of the static potential is
recovered, but the string tension is a little larger than the physical one.Comment: 21pages,4figures,to be published in JHE
String tension and glueball masses of SU(2) QCD from perfect action for monopoles and strings
We study the perfect monopole action as an infrared effective theory of SU(2)
QCD. It is transformed exactly into a lattice string model. Since the monopole
interactions are weak in the infrared SU(2) QCD, the string interactions become
strong. The strong coupling expansion of string model shows the quantum
fluctuation is small. The classical string tension is estimated analytically,
and we see it is very close to the quantum one in the SU(2) QCD. We also
discuss how to calculate the glueball mass in our model.Comment: LATTICE99(Confinement), 3 pages and 1 EPS figure
Clustering of Far-Infrared Galaxies in the AKARI All-Sky Survey
We present the first measurement of the angular two-point correlation
function for AKARI 90-m point sources, detected outside of the Milky Way
plane and other regions characterized by high Galactic extinction, and
categorized as extragalactic sources according to our far-infrared-color based
criterion (Pollo et al. 2010). This is the first measurement of the large-scale
angular clustering of galaxies selected in the far-infrared after IRAS
measurements. Although a full description of clustering properties of these
galaxies will be obtained by more detailed studies, using either spatial
correlation function, or better information about properties and at least
photometric redshifts of these galaxies, the angular correlation function
remains the first diagnostics to establish the clustering properties of the
catalog and observed galaxy population. We find a non-zero clustering signal in
both hemispheres extending up to degrees, without any significant
fluctuations at larger scales. The observed correlation function is well fitted
by a power law function. The notable differences between a northern and
southern hemisphere are found, which can be probably attributed to the
photometry problems and point out to a necessity of performing a better
calibration in the data from southern hemisphere.Comment: 6 pages, 6 figures, accepted for publication in Earth, Planets, and
Spac
Effective Monopole Action at Finite Temperature in SU(2) Gluodynamics
Effective monopole action at finite temperature in SU(2) gluodynamics is
studied on anisotropic lattices. Using an inverse Monte-Carlo method and the
blockspin transformation for space directions, we determine 4-dimensional
effective monopole action at finite temperature. We get an almost perfect
action in the continuum limit under the assumption that the action is composed
of two-point interactions alone. It depends on a physical scale and the
temperature . The temperature-dependence appears with respect to the
spacelike monopole couplings in the deconfinement phase, whereas the timelike
monopole couplings do not show any appreciable temperature-dependence. The
dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2)))
at high temperature is the 3-dimensional Georgi-Glashow model ().
The latter is studied at the parameter region obtained from the dimensional red
uction. We compare the effective instanton action of with the
timelike monopole action obtained from (SU(2)). We find that both agree
very well for at large region. The dimensional reduction
works well also for the effective action.Comment: 34 pages, 23 figure
QCD Phase Transition at Finite Temperature in the Dual Ginzburg-Landau Theory
We study the pure-gauge QCD phase transition at finite temperatures in the
dual Ginzburg-Landau theory, an effective theory of QCD based on the dual Higgs
mechanism. We formulate the effective potential at various temperatures by
introducing the quadratic source term, which is a new useful method to obtain
the effective potential in the negative-curvature region. Thermal effects
reduce the QCD-monopole condensate and bring a first-order deconfinement phase
transition. We find a large reduction of the self-interaction among
QCD-monopoles and the glueball masses near the critical temperature by
considering the temperature dependence of the self-interaction. We also
calculate the string tension at finite temperatures.Comment: 13 pages, uses PHYZZX ( 5 figures - available on request from
[email protected]
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