Describing gluons at zero and finite temperature

Any description of gluons requires a well-defined gauge. This is complicated non-perturbatively by Gribov copies. A possible method-independent gauge definition to resolve this problem is presented and afterwards used to study the properties of gluons at any temperature. It is found that only chromo-electric properties reflect the phase transition. From these the gauge-invariant phase transition temperature is determined for SU(2) and SU(3) Yang-Mills theory independently.Comment: 3 pages, 1 figure. Talk given at "The 5-th International Conference on Quarks and Nuclear Physics", Beijing, China, and at "Quarks, Hadrons, and the Phase Diagram of QCD", St. Goar, Germany, both September 2009. Submitted to the QNP proceeding

A study of the influence of the gauge group on the Dyson-Schwinger equations for scalar-Yang-Mills systems

The particular choice of the gauge group for Yang-Mills theory plays an important role when it comes to the influence of matter fields. In particular, both the chosen gauge group and the representation of the matter fields yield structural differences in the quenched case. Especially, the qualitative behavior of the Wilson potential is strongly dependent on this selection. Though the algebraic reasons for this observation is clear, it is far from obvious how this behavior can be described besides using numerical simulations. Herein, it is investigated how the group structure appears in the Dyson-Schwinger equations, which as a hierarchy of equations for the correlation functions have to be satisfied. It is found that there are differences depending on both the gauge group and the representation of the matter fields. This provides insight into possible truncation schemes for practical calculations using these equations.Comment: 47 page

Infrared-suppressed gluon propagator in 4d Yang-Mills theory in a Landau-like gauge

The infrared behavior of the gluon propagator is directly related to confinement in QCD. Indeed, the Gribov-Zwanziger scenario of confinement predicts an infrared vanishing (transverse) gluon propagator in Landau-like gauges, implying violation of reflection positivity and gluon confinement. Finite-volume effects make it very difficult to observe (in the minimal Landau gauge) an infrared suppressed gluon propagator in lattice simulations of the four-dimensional case. Here we report results for the SU(2) gluon propagator in a gauge that interpolates between the minimal Landau gauge (for gauge parameter lambda equal to 1) and the minimal Coulomb gauge (corresponding to lambda = 0). For small values of lambda we find that the spatially-transverse gluon propagator D^tr(0,|\vec p|), considered as a function of the spatial momenta |\vec p|, is clearly infrared suppressed. This result is in agreement with the Gribov-Zwanziger scenario and with previous numerical results in the minimal Coulomb gauge. We also discuss the nature of the limit lambda -> 0 (complete Coulomb gauge) and its relation to the standard Coulomb gauge (lambda = 0). Our findings are corroborated by similar results in the three-dimensional case, where the infrared suppression is observed for all considered values of lambda.Comment: 5 pages, 2 figures, one figure with additional results and extended discussion of some aspects of the results added and some minor clarifications. In v3: Various small changes and addition

Film handling procedures for Skylab S-056 experiment

In a simulation conducted August 28, 1972, two rolls of Type SO-212 film were rewound in the sensitometer darkroom preparatory to processing. The first roll contained approximately 500 feet of film exposed to a resolution target and was unloaded from a can. The second roll of 1000 feet, with about 600 feet advanced to the takeup side, was in a flight magazine. The downloading and rewinding of this second roll of film is described in detail

Two- and three-point Green's functions in two-dimensional Landau-gauge Yang-Mills theory

The ghost and gluon propagator and the ghost-gluon and three-gluon vertex of two-dimensional SU(2) Yang-Mills theory in (minimal) Landau gauge are studied using lattice gauge theory. It is found that the results are qualitatively similar to the ones in three and four dimensions. The propagators and the Faddeev-Popov operator behave as expected from the Gribov-Zwanziger scenario. In addition, finite volume effects affecting these Green's functions are investigated systematically. The critical infrared exponents of the propagators, as proposed in calculations using stochastic quantization and Dyson-Schwinger equations, are confirmed quantitatively. For this purpose lattices of volume up to (42.7 fm)^2 have been used.Comment: 14 pages, 14 figures, 4 tables, references adde

Review of machine washing efficiency for original film

Further silver sulfide stain tests for wash efficiency were conducted with major emphasis on means by which archival keeping quality may be achieved for original mission film

Non-commutative calculus, optimal transport and functional inequalities in dissipative quantum systems

We study dynamical optimal transport metrics between density matrices associated to symmetric Dirichlet forms on finite-dimensional $C^*$-algebras. Our setting covers arbitrary skew-derivations and it provides a unified framework that simultaneously generalizes recently constructed transport metrics for Markov chains, Lindblad equations, and the Fermi Ornstein--Uhlenbeck semigroup. We develop a non-nommutative differential calculus that allows us to obtain non-commutative Ricci curvature bounds, logarithmic Sobolev inequalities, transport-entropy inequalities, and spectral gap estimates