136 research outputs found
Deconfinement transition and monopoles in QCD
The role of monopoles in the deconfinement transition is discussed in the
framework of abelian projection in the maximally abelian gauge in
QCD. Only one (or a few near ) long connected monopole loop
exists uniformly through the whole lattice in each vacuum configuration in
addition to some very short loops in the confinement phase and the long loop
disappears in the deep deconfinement region. Energy-entropy balance of the long
loops of maximally extended monopoles explains the existence of the
deconfinement transition and reproduces roughly the value of the critical
temperature.Comment: 23 pages (14 figures) ,late
Monopoles and deconfinement transition in finite temperature QCD
We investigate the role of monopoles in the deconfinement transition of
finite temperature QCD in the maximally abelian gauge. In the
confinement phase a long monopole loop exists in each configuration, whereas no
long loop exists in the deep deconfinement region. Balancing of the energy and
the entropy of loops of the maximally extended monopoles can explain the
occurrence of the deconfinement transition.Comment: 3 pages (4 figures). Contribution to Lattice '9
Critical exponents and abelian dominance in QCD
The critical properties of the abelian Polyakov loop and the Polyakov loop in
terms of Dirac string are studied in finite temperature abelian projected
QCD. We evaluate the critical point and the critical exponents from
each Polyakov loop in the maximally abelian gauge using the finite-size scaling
analysis. Abelian dominance in this case is proved quantitatively. The critical
point of each abelian Polyakov loop is equal to that of the non-abelian
Polyakov loop within the statistical errors. Also, the critical exponents are
in good agreement with those from non-abelian Polyakov loops.Comment: 14 pages, latex, 4 figure
Study of gauge (in)dependence of monopole dynamics
We investigated the gauge (in)dependence of the confinement mechanism due to
monopole condensation in SU(2) lattice QCD by various abelian projections. We
found (1) the string tension can be reproduced by monopoles alone also in
Polyakov gauge and (2) the behaviors of the Polyakov loop at the critical
temperature seem to be explained by the uniformity breaking of the monopole
currents in every gauge.Comment: 4pages (7 figures), Latex, Contribution to Lattice 9
Three topics of monopole dynamics in abelian projected QCD
Three topics about monopole dynamics after abelian projection are reported.
The first is the new and detailed analyses of monopole action obtained
after the block-spin transformation on the dual lattice. The
dependence for all couplings are well fitted with a universal curve. The
distance dependence of the couplings is well reproduced by a massive propagator
with the mass in unit of . The second is the monopole action
recently obtained. The third is new interesting gauges showing abelian and
monopole dominances as in the maximally abelian gauge.Comment: Talk presented at LATTICE96(topology), 4 Pages, 7 eps figure
String tension and monopoles in SU(2) QCD
Monopole and photon contributions to abelian Wilson loops are calculated
using Monte-Carlo simulations of finite-temperature QCD in the
maximally abelian gauge. Long monopole loops alone are responsible for the
behavior of the string tension in the confinement phase up to the critical
. Short monopole loops and photons do not contribute to the string
tension. The abelian and the monopole spacial string tensions (both of which
agree with the normal ones for ) show a scaling
behavior in the deconfinement phase. The abelian spacial string tension is in
agreement with the full one even in the deconfinement phase.Comment: 10 Pages + 1 table + 8 figures, KANAZAWA 94-1
Reconfiguration of Time-Respecting Arborescences
An arborescence, which is a directed analogue of a spanning tree in an
undirected graph, is one of the most fundamental combinatorial objects in a
digraph. In this paper, we study arborescences in digraphs from the viewpoint
of combinatorial reconfiguration, which is the field where we study
reachability between two configurations of some combinatorial objects via some
specified operations. Especially, we consider reconfiguration problems for
time-respecting arborescences, which were introduced by Kempe, Kleinberg, and
Kumar. We first prove that if the roots of the initial and target
time-respecting arborescences are the same, then the target arborescence is
always reachable from the initial one and we can find a shortest
reconfiguration sequence in polynomial time. Furthermore, we show if the roots
are not the same, then the target arborescence may not be reachable from the
initial one. On the other hand, we show that we can determine whether the
target arborescence is reachable form the initial one in polynomial time.
Finally, we prove that it is NP-hard to find a shortest reconfiguration
sequence in the case where the roots are not the same. Our results show an
interesting contrast to the previous results for (ordinary) arborescences
reconfiguration problems.Comment: 13 pages, 3 figures, WADS 202
Gauge problem of monopole dynamics in SU(2) lattice gauge theory
金沢大学総合メディア基盤センター The gauge problem of monopole dynamics is studied in SU(2) lattice gauge theory. We study first the Abelian and monopole contributions to the static potential in four smooth gauges, i.e., the Laplacian Abelian, maximally Abelian Wilson loop, and L-type gauges in comparison with the maximally Abelian (MA) gauge. They all reproduce the string tension in good agreement with the SU(2) string tension. The MA gauge is not the only choice of a good gauge which is suitable for the color confinement mechanism. Using an inverse Monte Carlo method and block spin transformation, we determine the effective monopole actions and the renormalization group (RG) flows of its coupling constants in various Abelian projection schemes. Every RG flow appears to converge to a unique curve which suggests gauge independence in the infrared region. © 2003 The American Physical Society
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