Critical exponents for higher-representation sources in 3D SU(3) gauge theory from CFT

We establish an exact mapping between the multiplication table of the irreducible representations of SU(3) and the fusion algebra of the two-dimensional conformal field theory in the same universality class of 3D SU(3) gauge theory at the deconfining point. In this way the Svetitsky-Yaffe conjecture on the critical behaviour of Polyakov lines in the fundamental representation naturally extends to whatever representation one considers. As a consequence, the critical exponents of the correlators of these Polyakov lines are determined. Monte Carlo simulations with sources in the symmetric two-index representation, combined with finite-size scaling analysis, compare very favourably with these predictions.Comment: 15 pages, 2 figure

Self-avoiding effective strings in lattice gauge theories

It is shown that the effective string recently introduced to describe the long distance dynamics of 3D gauge systems in the confining phase has an intriguing description in terms of models of 2D self-avoiding walks in the dense phase. The deconfinement point, where the effective string becomes N=2 supersymmetric, may then be interpreted as the tricritical Theta point where the polymer chain undergoes a collapse transition. As a consequence, a universal value of the deconfinement temperature is predicted.Comment: 7 page

The Effective String of 3D Gauge Systems at the Deconfining Transition

It is argued that the effective string of whatever 3D gauge system at the deconfining transition is universally described by the minimal $N=2$ extended superconformal theory at $c=1$. A universal value of the critical temperature is predicted.Comment: 5 page

The Width of the Colour Flux Tube

We discuss and rederive in a general way the logarithmic growth of the mean squared width of the colour flux tube as a function of the interquark separation. Recent data on 3D $Z_2$ gauge theory, combined with high precision data on the interface physics of the 3D Ising model fit nicely this behaviour over a range of more than two orders of magnitude.Comment: 3 pages, contribution to the Lattice '94 conference, uuencoded compressed ps-fil

Thermal operators and cluster topology in q-state Potts Model

We discuss a new class of identities between correlation functions which arise from a local Z_2 invariance of the partition function of the q-state Potts model on general graphs or lattices. Their common feature is to relate the thermal operators of the Potts model to some topological properties of the Fortuin-Kasteleyn clusters. In particular it turns out that any even correlation function can be expressed in terms of observables which probe the linking properties of these clusters. This generalises a class of analogous relations recently found in the Ising model.Comment: 6 pages, latex, enlarged version, accepted for publication in Journal of Physics

The bulk kinetic power of the jets of GRS 1915+105

We calculate the minimum value of the power in kinetic bulk motion of the galactic superluminal source GRS 1915+105. This value far exceeds the Eddington luminosity for accretion onto a black hole of 10 solar masses. This large value severely limits the possible carriers of the kinetic luminosity at the base of the jet, and favours a jet production and acceleration controlled by a magnetic field whose value, at the base of the jet, exceeds $10^8$ Gauss. The Blandford and Znajek process can be responsible of the extraction of the rotational energy of a Kerr black hole, if lasting long enough to provide the required kinetic energy. This time, of the order of a day, implies that the process must operate in a stationary, not impulsive, mode.Comment: 5 pages, Latex, accepted for publication in MNRAS as a lette

Center vortices, magnetic condensate and confinement in a simple gauge system

The confining mechanisms of 't Hooft and Mandelstam have a simple microscopic realization in 3D Z2 gauge theory: the center vortex and the magnetic monopole condensation are associated, in the set of configurations contributing to the confining phase, to the presence of two kinds of infinite clusters. These generate the area law of the large Wilson loops and the universal finite size effects produced by the quantum fluctuations of the bosonic string describing the infrared behavior of the flux tube.Comment: 8 pages, 4 eps figures. Contributed to NATO Advanced Research Workshop on Confinement, Topology, and other Nonperturbative Aspects of QCD, Stara Lesna, Slovakia, 21-27 Jan 200

A simple algorithm to test for linking to Wilson loops in percolation

A simple burning or epidemic type of algorithm is developed in order to test whether any loops in percolation clusters link a fixed reference loop, a problem considered recently by Gliozzi, Lottini, Panero, and Rago in the context of gauge theory. We test our algorithm at criticality in both 2d, where the behavior agrees with a theoretical prediction, and in 3d.Comment: v1: A third figure added with additional simulation results. Small corrections als