Dirac sheets and gauge fixing in U(1)U(1) lattice gauge theory

Photon correlators in $~U(1)~$ pure gauge theory for different lattice actions are considered under the Lorentz gauge condition. They are shown to depend strongly on the gauge fixing ambiguity and on the corresponding existence of Dirac sheets. For the Coulomb phase a gauge fixing algorithm is proposed which avoids Dirac sheets and allows to find the global extremum of the non-local gauge condition. Sorry, figures are not included and can be sent by ordinary mail.Comment: 11 pages preprint HU Berlin--IEP--93/2, June 199

On higher spins and the tensionless limit of String Theory

We discuss string spectra in the low-tension limit using the BRST formalism, with emphasis on the role of triplets of totally symmetric tensors and spinor-tensors and their generalizations to cases with mixed symmetry and to (A)dS backgrounds. We also present simple compensator forms of the field equations for individual higher-spin gauge fields that display the {unconstrained} gauge symmetry of a previous non-local construction and reduce upon partial gauge fixing to the (Fang-)Fronsdal equations. For Bose fields we also show how a local Lagrangian formulation with {unconstrained} gauge symmetry is determined by a previous BRST construction.Comment: 44 pages, LATEX. Improper interpretation of gauge-fixing procedure for (A)dS triplet removed, misprints corrected, references adde

Gauge fixing in the tensor model and emergence of local gauge symmetries

The tensor model can be regarded as theory of dynamical fuzzy spaces, and gives a way to formulate gravity on fuzzy spaces. It has recently been shown that the low-lying fluctuations around the Gaussian background solutions in the tensor model agree correctly with the metric fluctuations on the flat spaces with general dimensions in the general relativity. This suggests that the local gauge symmetry (the symmetry of local translations) is also emergent around these solutions. To systematically study this possibility, I apply the BRS gauge fixing procedure to the tensor model. The ghost kinetic term is numerically analyzed, and it has been found that there exist some massless trajectories of ghost modes, which are clearly separated from the other higher ghost modes. Comparing with the corresponding BRS gauge fixing in the general relativity, these ghost modes forming the massless trajectories in the tensor model are shown to be identical to the reparametrization ghosts in the general relativity.Comment: 18 pages, 5 figure

Geometric Second Order Field Equations for General Tensor Gauge Fields

Higher spin tensor gauge fields have natural gauge-invariant field equations written in terms of generalised curvatures, but these are typically of higher than second order in derivatives. We construct geometric second order field equations and actions for general higher spin boson fields, and first order ones for fermions, which are non-local but which become local on gauge-fixing, or on introducing auxiliary fields. This generalises the results of Francia and Sagnotti to all representations of the Lorentz group.Comment: 34 pages, LaTeX. Reference adde

Migration with local public goods and the gains from changing places

Without public goods and under fairly standard assumptions, in Hammond and Sempere (J Pub Econ Theory, 8: 145–170, 2006) we show that freeing migration enhances the potential Pareto gains from free trade. Here, we present a generalization allowing local public goods subject to congestion. Unlike the standard literature on fiscal externalities, our result relies on fixing both local public goods and congestion levels at their status quo values. This allows constrained efficient and potentially Pareto improving population exchanges regulated only through appropriate residence charges, which can be regarded as Pigouvian congestion taxes

Conifold geometries, matrix models and quantum solutions

This paper is a continuation of hepth/0507224 where open topological B-models describing D-branes on 2-cycles of local Calabi--Yau geometries with conical singularities were studied. After a short review, the paper expands in particular on two aspects: the gauge fixing problem in the reduction to two dimensions and the quantum matrix model solutions.Comment: 17 p. To appear in proc. Symposium QTS-4, Varna (Bulgaria), August 200

Corruption in Australian sport

Examines some of the events that have affected the integrity of Australian sport between 2009–13 to describe the way in which corruption has manifested, the environment that has engendered the corrupt behaviour and the extent to which these incidents were primarily local events involving local actors. Forward Corruption in Australian sport is not a new phenomenon. A series of high-profile cases in Australia, combined with an increasing international focus, has seen a reassessment of Australian sport’s vulnerability to illegal activities such as match-fixing, use of inside information for betting purposes and the use of performance and image-enhancing drugs. This has led to the development and endorsement of national policies on match-fixing and doping, the establishment of sport integrity units, inclusion of specialist intelligence units in law enforcement and the creation of new match-fixing offences. Yet the actual extent of corruption in Australian sport remains unclear. In particular, does it exist more in the form of a threat rather than an intrinsic or widespread problem? This paper examines some of the events that have affected the integrity of Australian sport between 2009–13 to describe the way in which corruption has manifested, the environment that has engendered the corrupt behaviour and the extent to which these incidents were primarily local events involving local actors. It also proposes situational crime prevention techniques that may assist in framing and responding to corruption in Australian sport. Adam Tomison Directo