A phase transition due to thick vortices in SU(2) lattice gauge theory

SU(2) lattice gauge theory is studied after eliminating thin monopoles and the smallest thick monopoles. Kinematically this constraint allows thick vortex loops which produce long range Z(2) fluctuations. The thick vortex loops are identified in a three dimensional simulation. A condensate of thick vortices persists even after the thin vortices have all disappeared. They decouple at a slightly lower temperature (higher $\beta$) than the thin vortices and drive a Z(2) like phase transition.Comment: 3 pages, 3 figures (ps), Lattice 2002(Topology

Dual Abrikosov vortex between confined charges

We show that the dual Abrikosov vortex between quark and antiquark in Abelian Projected SU(2) gauge theory is insensitive to truncation of all loops except the large monopole cluster noted by Hart and Teper. As the transverse distance increases, the discrepancy decreases, suggesting that the London penetration depth determined by the tail is invariant under the truncation of short loops.Comment: Latex, tar-compressed file, two figures, Lattice 2002 contributed tal

Axial anomaly and Ginsparg-Wilson fermions in the Lattice Dirac Sea picture

The axial anomaly equation in 1+1 dimensional QED is obtained on the lattice for fermions obeying the Ginsparg-Wilson relation. We make use of the properties of the Lattice Dirac sea to investigate the connection between the anomaly and the Ginsparg-Wilson operator in the Hamiltonian picture. The correct anomaly is reproduced for gauge fields whose characteristic time is much larger than the lattice spacing, which is the regime where the adiabatic approximation applies. A non-zero Wilson $r$ parameter is necessary to get the correct anomaly. The anomaly is shown to be independent of $r$ for $r>0.5$. The generalization to 3+1 dimensions is also discussed.Comment: 19 pages latex,12 figures; manuscript revised, references adde

Dual variables for the SU(2) lattice gauge theory at finite temperature

We study the three-dimensional SU(2) lattice gauge theory at finite temperature using an observable which is dual to the Wilson line. This observable displays a behaviour which is the reverse of that seen for the Wilson line. It is non-zero in the confined phase and becomes zero in the deconfined phase. At large distances, it's correlation function falls off exponentially in the deconfined phase and remains non-zero in the confined phase. The dual variable is non-local and has a string attached to it which creates a Z(2) interface in the system. It's correlation function measures the string tension between oppositely oriented Z(2) domains. The construction of this variable can also be made in the four-dimensional theory where it measures the surface tension between oppositely oriented Z(2) domains.Comment: 13 pages, LaTeX, 4 figures are included in the latex fil

A lattice model with a theta term in three dimensions

We study a three-dimensional abelian lattice model in which the analogue of a theta term can be defined. This term is defined by introducing a neutral scalar field and its effect is to couple magnetic monopoles to the scalar field and vortices to the gauge field. An interesting feature of this model is the presence of an exact duality symmetry that acts on a three parameter space. It is shown that this model has an interesting phase structure for non-zero values of theta. In addition to the usual confinement and vortex phases there are phases in which loops with composite charges condense. The presence of novel point like excitations also alters the physical properties of the system.Comment: 32 pages in latex and three figure