To what distances do we know the confining potential?

We argue that asymptotically linear static potential is built in into the common procedure of extracting it from lattice Wilson loop measurements. To illustrate the point, we extract the potential by the standard lattice method in a model vacuum made of instantons. A beautiful infinitely rising linear potential is obtained in the case where the true potential is actually flattening. We argue that the flux tube formation might be also an artifact of the lattice procedure and not necessarily a measured physical effect. We conclude that at present the rising potential is known for sure up to no more than about 0.7 fm. It may explain why no screening has been clearly observed so far for adjoint sources and for fundamental sources but with dynamical fermions. Finally, we speculate on how confinement could be achieved even if the static potential in the pure glue theory is not infinitely rising.Comment: 16 pages, 5 figures. Additional arguments presented, a new figure and references adde

Can a Logarithmically Running Coupling Mimic a String Tension?

It is shown that a Coulomb potential using a running coupling slightly modified from the perturbative form can produce an interquark potential that appears nearly linear over a large distance range. Recent high-statistics SU(2) lattice gauge theory data fit well to this potential without the need for a linear string-tension term. This calls into question the accuracy of string tension measurements which are based on the assumption of a constant coefficient for the Coulomb term. It also opens up the possibility of obtaining an effectively confining potential from gluon exchange alone.Comment: 13 pages, LaTeX, two figures not included, available from author. revision - Line lengths fixed so it will tex properl

Annual Survey of Virginia Law: Criminal Law

This article summarizes most published criminal law decisions of the Supreme Court of Virginia and the Virginia Court ofAppeals sitting en banc, issued between July 1, 1998 and July 1, 1999. This article also includes selected published panel opinions oftheVirginia Court of Appeals and a summary of the most significant criminal law enactments from the 1999 session of the Virginia General Assembly

The Schwinger Model on the lattice in the Microcanonical Fermionic Average approach

The Microcanonical Fermionic Average method has been used so far in the context of lattice models with phase transitions at finite coupling. To test its applicability to Asymptotically Free theories, we have implemented it in QED$_2$, \it i.e.\rm the Schwinger Model. We exploit the possibility, intrinsic to this method, of studying the whole $\beta, m$ plane at negligible computer cost, to follow constant physics trajectories and measure the $m \to 0$ limit of the chiral condensate. We recover the continuum result within 3 decimal places.Comment: TeX file, 7 pages + 3 figures in Postscrip

Identification (or otherwise) of martian carbon in martian meteorites

One of the goals of current martian exploration is to search for evidence of extinct (or even extant) life. In recent years, this goal has been interpreted as a search for evidence of water on Mars’ surface. The success of instrumentation (high resolution cameras and infrared spectrometers) on orbiting spacecraft, coupled with in situ data from the MER rovers have revolutionized our understanding of the surface of Mars, the type of rocks and minerals pre-sent, and their stratigraphy [1 and subsequent papers]. It is clear that there has been extensive and intensive aqueous action at different periods in Mars’ history, and evidence for water is, to all intents and purposes, irrefutable. It is now time to define the next phase in the search for life as a search for regions of habitability on Mars [2]. A search for life could also be seen as a search for carbon, as one of the major assumptions that has been made in the search for life on Mars is that any life present is likely to be carbon-based

Monopole Percolation in pure gauge compact QED

The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter $n_{max}/n_{tot}$ previously introduced by Hands and Wensley in the study of the percolation transition observed in non-compact QED. A correlation between these parameters and the energy (action) at the phase transition has been observed. We conclude that the order parameter $n_{max}/n_{tot}$ is a sensitive probe for studying the phase transition of pure gauge compact QED.Comment: LaTeX file + 4 PS figures, 12 pag., Pre-UAB-FT-308 ILL-(TH)-94-1

A Compact Linear Programming Relaxation for Binary Sub-modular MRF

We propose a novel compact linear programming (LP) relaxation for binary sub-modular MRF in the context of object segmentation. Our model is obtained by linearizing an $l_1^+$-norm derived from the quadratic programming (QP) form of the MRF energy. The resultant LP model contains significantly fewer variables and constraints compared to the conventional LP relaxation of the MRF energy. In addition, unlike QP which can produce ambiguous labels, our model can be viewed as a quasi-total-variation minimization problem, and it can therefore preserve the discontinuities in the labels. We further establish a relaxation bound between our LP model and the conventional LP model. In the experiments, we demonstrate our method for the task of interactive object segmentation. Our LP model outperforms QP when converting the continuous labels to binary labels using different threshold values on the entire Oxford interactive segmentation dataset. The computational complexity of our LP is of the same order as that of the QP, and it is significantly lower than the conventional LP relaxation

Simulation and Field Verification of Vehicle-Loop Interactions

Inductive sensors are used worldwide for traffic control. These sensors consist of a loop or loops of wire embedded in the pavement. The loops are connected to electronic control circuits that convert changes in loop inductance to signals to control traffic lights or to monitor traffic. This work describes a simulation approach that permits reliable calculation of the response of loops of various geometries to various types of vehicles. The simulation models both the loop and the vehicles with a set of filaments of finite length. The simulation approach was validated using two different loop geometries and various types of vehicles. The simulation was developed to assist in the selection of a loop geometry for a particular application or to assess the likely behavior of hypothetical loops. As it is based on a fundamental description of the vehicle-loop interaction, the simulation approach is also expected to be useful in other investigations of loop responses.Center for Electromechanic