1,781 research outputs found
Monopole action from vacuum configurations in compact QED
It is possible to derive a monopole action from vacuum configurations
obtained in Monte-Carlo simulations extending the method developed by Swendsen.
We apply the method to compact QED both in the Villain and in the Wilson forms.
The action of the natural monopoles in the Villain case is in fairly good
agreement with that derived by the exact dual transformation. Comparing the
monopole actions, we find (1) the DeGrand-Toussaint monopole definition may be
useful for larger than about 0.5, (2) the Villain model well
approximates the Wilson one for smaller than and (3) in the
Wilson action the monopole condensation occurs in the confinement phase and
may be explained by the energy-entropy balance of monopole loops like
in the Villain case.Comment: 12 Pages+7 figures, KANAZAWA 94-1
Monopole Condensation and Confinement in SU(2) QCD (1)
An effective monopole action is derived from vacuum configurations after
abelian projection in the maximally abelian gauge in QCD. Entropy
dominance over energy of monopole loops is seen on the renormalized lattice
with the spacing when the
physical volume of the system is large enough. QCD confinement may be
interpreted as the (dual) Meissner effect due to the monopole condensation.Comment: 12 pages, KANAZAWA 93-0
Block spin transformation on the dual lattice and monopole action
To find a perfect lattice action in terms of monopole action on the dual
lattice, we performed simulations of a monopole effective action obtained
numerically from vacuum configurations in SU(2) QCD. Although the Polyakov loop
behavior near is well reproduced by the action, a small but repulsive
term is needed in addition to get the string tension correctly. It is reported
also a monopole effective action in QCD which is expressed by one kind
of monopole currents.Comment: 4pages (4 figures), Latex, Contribution to Lattice 9
Replica Monte Carlo Simulation (Revisited)
In 1986, Swendsen and Wang proposed a replica Monte Carlo algorithm for spin
glasses [Phys. Rev. Lett. 57 (1986) 2607]. Two important ingredients are
present, (1) the use of a collection of systems (replicas) at different of
temperatures, but with the same random couplings, (2) defining and flipping
clusters. Exchange of information between the systems is facilitated by fixing
the tau spin (tau=sigma^1\sigma^2) and flipping the two neighboring systems
simultaneously. In this talk, we discuss this algorithm and its relationship to
replica exchange (also known as parallel tempering) and Houdayer's cluster
algorithm for spin glasses. We review some of the early results obtained using
this algorithm. We also present new results for the correlation times of
replica Monte Carlo dynamics in two and three dimensions and compare them with
replica exchange.Comment: For "Statistical Physics of Disordered Systems and Its Applications",
12-15 July 2004, Shonan Village Center, Hayama, Japan, 7 page
Monopole action and condensation in SU(2) QCD
An effective monopole action for various extended monopoles is derived from
vacuum configurations after abelian projection in the maximally abelian gauge
in QCD. The action appears to be independent of the lattice volume.
Moreover it seems to depend only on the physical lattice spacing of the
renormalized lattice, not on . Entropy dominance over energy of monopole
loops is seen on the renormalized lattice with the spacing . This suggests that monopole condensation
always (for all ) occurs in the infinite-volume limit of lattice QCD.Comment: 15 Pages+7 figures, KANAZAWA 94-1
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