Dynamic roughening of the magnetic flux landscape in YBa2_2Cu3_3O7−x_{7-x}

We study the magnetic flux landscape in YBa$_2$Cu$_3$O$_{7-x}$ thin films as a two dimensional rough surface. The vortex density in the superconductor forms a self-affine structure in both space and time. This is characterized by a roughness exponent $\alpha = 0.76(3)$ and a growth exponent $\beta = 0.57(6)$. This is due to the structure and distribution of flux avalanches in the self-organized critical state, which is formed in the superconductor. We also discuss our results in the context of other roughening systems in the presence of quenched disorder.Comment: 13 pages, 7 figures, accepted for publication in Physica

The Torus Universe in the Polygon Approach to 2+1-Dimensional Gravity

In this paper we describe the matter-free toroidal spacetime in 't Hooft's polygon approach to 2+1-dimensional gravity (i.e. we consider the case without any particles present). Contrary to earlier results in the literature we find that it is not possible to describe the torus by just one polygon but we need at least two polygons. We also show that the constraint algebra of the polygons closes.Comment: 18 pages Latex, 13 eps-figure

Broad Absorption Line Variability in Radio-Loud Quasars

We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of high-ionization BAL quasars, and a substantial fraction have large BAL velocities or equivalent widths; their radio luminosities and radio-loudness values span ~2.5 orders of magnitude. We have obtained 34 new Hobby-Eberly Telescope (HET) spectra of 28 BAL RLQs to compare to earlier SDSS data, and we also incorporate archival coverage (primarily dual-epoch SDSS) for a total set of 78 pairs of equivalent width measurements for 46 BAL RLQs, probing rest-frame timescales of ~80-6000 d (median 500 d). In general, only modest changes in the depths of segments of absorption troughs are observed, akin to those seen in prior studies of BAL RQQs. Also similar to previous findings for RQQs, the RLQs studied here are more likely to display BAL variability on longer rest-frame timescales. However, typical values of |Delta_EW| and |Delta_EW|/ are about 40+/-20% lower for BAL RLQs when compared with those of a timescale-matched sample of BAL RQQs. Optical continuum variability is of similar amplitude in BAL RLQs and BAL RQQs; for both RLQs and RQQs, continuum variability tends to be stronger on longer timescales. BAL variability in RLQs does not obviously depend upon their radio luminosities or radio-loudness values, but we do find tentative evidence for greater fractional BAL variability within lobe-dominated RLQs. Enhanced BAL variability within more edge-on (lobe-dominated) RLQs supports some geometrical dependence to the outflow structure.Comment: 27 pages, 16 figures, 6 tables, accepted to MNRAS, full Appendix A at http://www.macalester.edu/~bmille13/balrlqs.htm

The 2+1 Kepler Problem and Its Quantization

We study a system of two pointlike particles coupled to three dimensional Einstein gravity. The reduced phase space can be considered as a deformed version of the phase space of two special-relativistic point particles in the centre of mass frame. When the system is quantized, we find some possibly general effects of quantum gravity, such as a minimal distances and a foaminess of the spacetime at the order of the Planck length. We also obtain a quantization of geometry, which restricts the possible asymptotic geometries of the universe.Comment: 59 pages, LaTeX2e, 9 eps figure

Money Laundering and Lawyers

The federal government has recently enacted money laundering laws to track and discourage the use of money generated by crime. Because some of that money is used to pay legal fees, the laws have a direct impact on lawyers. The laws increase the risk of prosecution for lawyers, inhibit some methods of fee payment, and make some cases less attractive financially. Generally, the laws make law practice more complicated and risky. The laws have been criticized for their impact on criminal defense lawyers. Critics have raised three broad objections. The first objection is constitutional. Critics have also objected to the laws on ethical grounds, claiming that they force lawyers to act unethically. The third objection is based on the practical impact of the laws. Critics claim the laws chill the relationship between lawyers and clients, drive some lawyers out of criminal work, and give prosecutors too much power to disqualify defense lawyers. The constitutional questions have so far been resolved in favor of the government, but objections to the money laundering laws on the other two grounds need to be examined. Although the laws are constitutional as applied to criminal defense lawyers, the question remains whether that application is wise. Based on the laws’ ethical and practical impact, many claim that it is not. Nowhere in the literature have the laundering laws been analyzed in terms of their collective impact on criminal defense lawyers. This article does that analysis. It begins by examining how the federal money laundering laws apply to criminal defense lawyers when they receive fees for their work. The article then explores whether and how the laws cause criminal defense lawyers to act unethically. The article next analyzes the practical impact of the laws on these lawyers. This article concludes that while the ethical criticisms of the laws are largely unfounded, there is legitimate, though as yet undocumented, concern about their practical impact on our criminal justice system

(2+1)-Gravity Solutions with Spinning Particles

We derive, in 2+1 dimensions, classical solutions for metric and motion of two or more spinning particles, in the conformal Coulomb gauge introduced previously. The solutions are exact in the $N$-body static case, and are perturbative in the particles' velocities in the dynamic two-body case. A natural boundary for the existence of our gauge choice is provided by some ``CTC horizons'' encircling the particles, within which closed timelike curves occur.Comment: 30 pages, LaTeX, no figure

Reproductive ecology of the Mountain Dragon, Rankinia (Tympanocryptis) diemensis (Reptilia: Squamata: Agamidae) in Tasmania

The mountain dragon, Rankinta (7ympanocryptis) diemensis (Gray, 1841), is the only member of the Agamidae in Tasmania. It occurs in some of the coldest regions occupied by any dragon in Australia, and is found in a variety of habitats ranging from coastal heath to alpine scrub. This paper examines the reproductive ecology of R. diemensis in the most southerly range of its distribution, providing baseline data on timing of reproductive events, reproductive cycles, nesting behaviour and ovipositioning, clutch characteristics and incubation conditions. Winter torpor lasts approximately seven months with males emerging in early September and spermatogenesis occurring from September-November. Females emerge later, with vitellogenesis occurring from September-December. Gravid females may be found between October and January, but females are non-vitellogenic from late December until the following season. The first clutch is typically laid from October--December, with a variable clutch size (2-11 eggs). Females store sperm and a second clutch may be laid five weeks after the first. Eggs incubated in artificial enclosures at low altitude hatched after 72--106 days, after experiencing an average daily temperature of 19°-22°C, and a range of 50-39°C