The periodic standing-wave approximation: nonlinear scalar fields, adapted coordinates, and the eigenspectral method

The periodic standing wave (PSW) method for the binary inspiral of black holes and neutron stars computes exact numerical solutions for periodic standing wave spacetimes and then extracts approximate solutions of the physical problem, with outgoing waves. The method requires solution of a boundary value problem with a mixed (hyperbolic and elliptic) character. We present here a new numerical method for such problems, based on three innovations: (i) a coordinate system adapted to the geometry of the problem, (ii) an expansion in multipole moments of these coordinates and a filtering out of higher moments, and (iii) the replacement of the continuum multipole moments with their analogs for a discrete grid. We illustrate the efficiency and accuracy of this method with nonlinear scalar model problems. Finally, we take advantage of the ability of this method to handle highly nonlinear models to demonstrate that the outgoing approximations extracted from the standing wave solutions are highly accurate even in the presence of strong nonlinearities.Comment: RevTex, 32 pages, 13 figures, 6 table

Avon Park Air Force Range project: distribution and abundance of sensitive wildlife species at Avone Park Force Range

Executive Summary. We surveyed for seven species ofsensitve wildlife (Florida gopher frogs, gopher tortoise, eastern indigo snake, eastern diamondback rattlesnake, Florida mouse, Florida roundtail muskrat, Sherman's fox squirrel) between October 1996 and May 1998 at Avon Park Air Force Range (APR). The presence of 87 other species ofamphibians, reptiles, and mammals also were detected. Selected species ofbirds were noted, particularly if they were found dead on APR roads. We recorded nine new county records ofamphibians and reptiles from Polk and Highlands counties, based on range maps presented in Ashton and Ashton (1981, 1985, 1988). We discuss a biogeographic model based on the vertebrates recorded from APR, the Lake Wales Ridge, and the low dune region along SR 64 to explain some of the distributional anomalies associated with the Bombing Range Ridge and vicinity. (199 page document

Post-Louvre intervention: did target zones stabilize the dollar?

An investigation of whether the G-3 nations (Germany, Japan, and the U.S.) successfully maintained target zones following the G-7's February 1987 Louvre meeting. Using daily, official intervention data and simultaneous-equation techniques, the authors determine that the G-3 reacted in a manner consistent with maintaining target zones, but find scant evidence that the intervention successfully influenced subsequent exchange-rate movements.Foreign exchange - Law and legislation ; Dollar, American

Can the Market Add and Subtract? Mispricing in Tech Stock Carve-Outs

Recent equity carve-outs in US technology stocks appear to violate a basic premise of financial theory: identical assets have identical prices. In our 1998-2000 sample, holders of a share of company A are expected to receive x shares of company B, but the price of A is less than x times the price of B. A prominent example involves 3Com and Palm. Arbitrage does not eliminate these blatant mispricing due to short sale constraints, so that B is overpriced but expensive or impossible to sell short. Evidence from options prices shows that shorting costs are extremely high, eliminating exploitable arbitrage opportunities.

Testing gravitational parity violation with coincident gravitational waves and short gamma-ray bursts

Gravitational parity violation is a possibility motivated by particle physics, string theory and loop quantum gravity. One effect of it is amplitude birefringence of gravitational waves, whereby left and right circularly-polarized waves propagate at the same speed but with different amplitude evolution. Here we propose a test of this effect through coincident observations of gravitational waves and short gamma-ray bursts from binary mergers involving neutron stars. Such gravitational waves are highly left or right circularly-polarized due to the geometry of the merger. Using localization information from the gamma-ray burst, ground-based gravitational wave detectors can measure the distance to the source with reasonable accuracy. An electromagnetic determination of the redshift from an afterglow or host galaxy yields an independent measure of this distance. Gravitational parity violation would manifest itself as a discrepancy between these two distance measurements. We exemplify such a test by considering one specific effective theory that leads to such gravitational parity-violation, Chern-Simons gravity. We show that the advanced LIGO-Virgo network and all-sky gamma-ray telescopes can be sensitive to the propagating sector of Chern-Simons gravitational parity violation to a level roughly two orders of magnitude better than current stationary constraints from the LAGEOS satellites.Comment: 21 pages, 2 figures, submitted to Phys. Rev.

Lawzone: Mapping unmet legal need

Mapping unmet legal need assists university law clinics plan activities to meet the needs of the communities they serve.  This article, by looking at a project where students started mapping unmet legal need in their locality, will consider the pedagogical issues associated with identifying unmet legal need and how it might enable university law clinics to be better embedded into their local communities by considering aspects of physical and human geography when considering injustice.  It will also look at exiting research methodologies in this area and how mapping unmet legal need can develop students’ empirical research skills.  The article also assesses the project’s aims to develop attributes such as entrepreneurship, as well utilising teaching practices such as visualisation to enable students to think spatially to perceive and understand social inequalities more clearly.  It will argue that involving students in mapping unmet legal need will help them make those services more accessible; devise holistic solutions to clients’ problems; and enable them to work more effectively with other disciplines to both their own and their clients’ benefit

Sustainability and University Law Clinic

Following increased activism, the climate crisis has moved up the political agenda, and with it an increased interest in sustainability issues. This article will look at how rebellious lawyering theory can provide a template for university law clinics when seeking to further sustainability objectives. It argues that as rebellious lawyering methods require a collective dimension to lawyering, egalitarian collaboration, deep knowledge of the communities that lawyers serve, simulations of a better future, self-examination and the building of broad coalitions it can in certain circumstances be a more effective way of furthering sustainability objectives than traditional legal process. Furthermore, building broad coalitions is vital to maintain the impetus behind sustainability initiatives.It will reflect on the cultural change that is needed to respond to the sustainability agenda, what lessons can be learnt from the different approaches which have been taken internationally to the issue, as well as the pedagogical issues that need to be addressed to ensure that students have the appropriate sustainability literacy. It will also reflect on the extent to which sustainability is already embedded in the work of university law clinics.It will examine how university law clinics can respond to sustainable development legislation by using Swansea Law Clinic’s experiences of working with sustainability goals and approaches, in the form of the Well-being of Future Generations (Wales) Act 2015, as a case study

Physical processes in polar stratospheric ice clouds

A one dimensional model of cloud microphysics was used to simulate the formation and evolution of polar stratospheric ice clouds. Some of the processes which are included in the model are outlined. It is found that the clouds must undergo preferential nucleation upon the existing aerosols just as do tropospheric cirrus clouds. Therefore, there is an energy barrier between stratospheric nitric acid particles and ice particles implying that nitric acid does not form a continuous set of solutions between the trihydrate and ice. The Kelvin barrier is not significant in controlling the rate of formation of ice particles. It was found that the cloud properties are sensitive to the rate at which the air parcels cool. In wave clouds, with cooling rates of hundreds of degrees per day, most of the existing aerosols nucleate and become ice particles. Such clouds have particles with sizes on the order of a few microns, optical depths on order of unity and are probably not efficient at removing materials from the stratosphere. In clouds which form with cooling rates of a few degrees per day or less, only a small fraction of the aerosols become cloud particles. In such clouds the particle radius is larger than 10 microns, the optical depths are low and water vapor is efficiently removed. Seasonal simulations show that the lowest water vapor mixing ratio is determined by the lowest temperature reached, and that the time when clouds disappear is controlled by the time when temperatures begin to rise above the minimum values