Monopoles, confinement and the photon propagator in QED3_3

We study the lattice gauge boson propagator of 3D compact QED in Landau gauge at zero and non-zero temperature. Non-perturbative effects are reflected by the generation of a mass $m$, by an anomalous dimension $\alpha$ and by the photon wave function renormalisation $Z$. These effects can be attributed to monopoles: they are absent in the propagator of the regular part of the gauge field. The r\^ole of Gribov copies is carefully investigated.Comment: 3 pages, 5 figures, Lattice2002(topology

The photon propagator in compact QED_{2+1}: the effect of wrapping Dirac strings

We discuss the influence of closed Dirac strings on the photon propagator in the Landau gauge emerging from a study of the compact U(1) gauge model in 2+1 dimensions. This gauge also minimizes the total length of the Dirac strings. Closed Dirac strings are stable against local gauge-fixing algorithms only due to the torus boundary conditions of the lattice. We demonstrate that these left-over Dirac strings are responsible for the previously observed unphysical behavior of the propagator of space-like photons (D_T) in the deconfinement (high temperature) phase. We show how one can monitor the number N_3 of thermal Dirac strings which allows to separate the propagator measurements into N_3 sectors. The propagator in N_3 \neq 0 sectors is characterized by a non--zero mass and an anomalous dimension similarly to the confinement phase. Both mass squared and anomalous dimension are found to be proportional to N_3. Consequently, in the N_3=0 sector the unphysical behavior of the D_T photon propagator is cured and the deviation from the free massless propagator disappears.Comment: 13 pages, 13 figures, 1 tabl

Energy-entropy study of projected space-like monopoles in finite-T quenched SU(2) QCD

Properties of space-like monopoles projected on the 3D space in finite temperature quenched SU(2) QCD are studied. The monopole energy is derived from the effective action of the monopoles which is determined by an inverse Monte-Carlo method. Then the entropy is fixed with the help of the monopole-loop distribution.Comment: 3 pages, 6 figures, uses espcrc2.sty; Lattice2003(topology

Blocking of lattice monopoles from the continuum in hot lattice gluodynamics

The Abelian monopoles in lattice gluodynamics are associated with continuum monopoles blocked to the lattice. This association allows to predict the lattice monopole action and density of the (squared) monopole charges from a continuum monopole model. The method is applied to the static monopoles in high temperature gluodynamics. We show that the numerical data both for the density and the action of the lattice monopoles can be described in terms of a Coulomb gas of Abelian monopoles in the continuum.Comment: 23 pages, 9 EPS figures, LaTeX2e uses JHEP3 class file; replaced to match published versio

Short Range Linear Potential in 3D Lattice Compact QED

We study the static potential between electric charges in the finite temperature three dimensional compact gauge theory on the lattice. We show that in the deconfinement phase at small separations between the charges the potential contains a linearly rising piece which goes over into the Coulomb potential as the distance between the charges is increased. The linear potential is due to the gas of magnetic dipoles which are realized as monopole-antimonopole bound states.Comment: 10 pages, 6 EPS figures, LaTeX2e, uses epsfig.st

Monopole creation operators as confinement--deconfinement order parameters

We study numerically two versions of the monopole creation operators proposed by Frohlich and Marchetti. The disadvantage of the old version of the monopole creation operator is due to visibility of the Dirac string entering the definition of the creation operator in the theories with coexisting electric and magnetic charges. This problem does not exist for the new creation operator which is rather complicated. Using the Abelian Higgs model with a compact gauge field we show that both definitions of the monopole creation operator can serve as order parameters for the confinement--deconfinement phase transition. The value of the monopole condensate for the old version depends on the length of Dirac string. However, as soon as the length is fixed the old operator certainly discriminates between the phases with condensed and non--condensed monopoles.Comment: 12 pages, 7 figures, LaTeX2

Vortex profiles and vortex interactions at the electroweak crossover

Local correlations of Z-vortex operators with gauge and Higgs fields (lattice quantum vortex profiles) as well as vortex two-point functions are studied in the crossover region near a Higgs mass of 100 GeV within the 3D SU(2) Higgs model. The vortex profiles resemble certain features of the classical vortex solutions in the continuum. The vortex-vortex interactions are analogous to the interactions of Abrikosov vortices in a type-I superconductor.Comment: talk at LATTICE99(electroweak), 3 pages and 5 EPS figure

Embedded Topological Defects in Hot Electroweak Theory: a Lattice Study

We study the properties of Nambu monopoles and Z-vortices in the 3D lattice SU(2) Higgs theory which represents the Standard Model at high temperature. We show that the densities of the Nambu monopoles and the Z-vortices are O(1) in the symmetric phase and generically small in the Higgs phase. Near to the critical Higgs mass and in the vicinity of the phase transition the densities are no more negligible in the broken phase. The percolation probability of the Z-vortex lines is found as a new disorder parameter for this phase transition. We conclude that the transition to the symmetric phase is accompanied by Z-vortex condensation. Simulations comparing elementary and extended vortices and monopoles at different \beta_G values, aiming to show that the density of vortices and monopoles of fixed physical size might have a well-defined continuum limit, gives encouraging but so far inconclusive results.Comment: 13 pages, LaTeX, 8 figures, epsf.sty needed; revision: minor changes and reference adde

Aharonov--Bohm Effect in 3D Abelian Higgs Theory

We study a field--theoretical analogue of the Aharonov--Bohm effect in the 3D Abelian Higgs Model: the corresponding topological interaction is proportional to the linking number of the vortex and the particle world trajectories. We show that the Aharonov--Bohm effect gives rise to a nontrivial interaction of tested charged particles.Comment: LaTeX, 3 pages, 1 figure, uses epsf.sty; talk presented at LATTICE96(topology), St. Louis, US

Electric and magnetic currents in SU(2) lattice gauge theory

The correlations of the topological charge (Q), the electric (Je) and the magnetic (Jm) currents in the SU(2) lattice gauge theory in the Maximal Abelian projection are investigated. A nonzero value of the correlator is obtained for a wide range of values of the bare charge, as well as under the cooling.Comment: 3 pages, 1 figure, LaTeX using espcrc2.sty and epsfig.sty; Talk given by F.V. Gubarev at the International Symposium on Lattice Field Theory, 22-26 July 1997, Edinburgh, Scotlan