Mass Degeneracies In Self-Dual Models

An algebraic restriction of the nonabelian self-dual Chern-Simons-Higgs systems leads to coupled abelian models with interesting mass spectra. The vacua are characterized by embeddings of $SU(2)$ into the gauge algebra, and in the broken phases the gauge and real scalar masses coincide, reflecting the relation of these self-dual models to $N=2$ SUSY. The masses themselves are related to the exponents of the gauge algebra, and the self-duality equation is a deformation of the classical Toda equations.Comment: 10 pages LaTeX (previous copy truncated

Supersymmetry Breaking with Periodic Potentials

We discuss supersymmetry breaking in some supersymmetric quantum mechanical models with periodic potentials. The sensitivity to the parameters appearing in the superpotential is more acute than in conventional nonperiodic models. We present some simple elliptic models to illustrate these points.Comment: 10 pp; Latex; 3 figures using eps

Edge Asymptotics of Planar Electron Densities

The $N\to\infty$ limit of the edges of finite planar electron densities is discussed for higher Landau levels. For full filling, the particle number is correlated with the magnetic flux, and hence with the boundary location, making the $N\to\infty$ limit more subtle at the edges than in the bulk. In the $n^{\rm th}$ Landau level, the density exhibits $n$ distinct steps at the edge, in both circular and rectangular samples. The boundary characteristics for individual Landau levels, and for successively filled Landau levels, are computed in an asymptotic expansion.Comment: 17pp including 5 figures, UCONN-93-

Content Neutrality: A Defense

To date, both the United States federal government and twenty-one individual states have passed Religious Freedom Restoration Acts that aim to protect religious persons from having their sincere beliefs substantially burdened by governmental interests. RFRAs accomplish this by offering a three-pronged exemption test for religious objectors that is satisfied only when (1) an objector has a sincere belief that is being substantially burdened; (2) the government has a very good reason (e.g., health or safety) to interfere; and (3) there is a reasonable alternative to serve the compelling interest. Legal balancing tests like those found in RFRA are content neutral insofar as they sideline the belief-content of conscientious objections as irrelevant when determining the permissibility of granting legal accommodations. However, some theorists worry that this legal picture may be backward: perhaps balancing tests should be content non-neutral given the usual features of conscientious objections. For example, Yossi Nehushtan contends that, contrary to their typical codification, religious conscience beliefs seem undeserving of special legal accommodations because they possess uniquely strong empirical and theoretical ties to intolerance. Thus, the illiberally intolerant content of these conscientious objections might actually give the state a reason to refuse to grant legal exemptions. In this paper, I offer a cursory defense of content neutrality with respect to balancing tests like those found in RFRA. To begin, I outline Nehushtan’s argument for content non-neutrality. The cornerstone of his argument is that illiberal intolerance is intolerable such that conscientious objections that are based upon illiberally intolerant values provide the state with strong, normally prevailing reason not to grant an exemption. I argue that, even when the illiberally intolerant content of one’s conscience constitutes a weighty and relevant factor in determining the permissibility of granting a legal exemption, there remain significant problems. It is difficult, for example, to determine which views are illiberally intolerant and difficult to say whether illiberally intolerant views can effectively serve as the principled demarcating line in balancing tests. To conclude, I offer several cursory arguments in favor of adopting content-neutral approaches without necessarily making a comprehensive case. By drawing on the work of Amy Sepinwall, Nadia Sawicki, and Nathan Chapman, I show that content-neutral approaches can help to safeguard robust protections for conscience by permitting atypical exercises of conscience, protect minority thoughts and practices from being coercively supplanted by majoritarian understandings of morality, appropriately maintain the skepticism and humility that we owe each other as compatriots in a pluralistic society, and allow the kind of justifiable civil disobedience that has an important place in political history among other things

An All-Orders Derivative Expansion

We evaluate the exact $QED_{2+1}$ effective action for fermions in the presence of a family of static but spatially inhomogeneous magnetic field profiles. This exact result yields an all-orders derivative expansion of the effective action, and indicates that the derivative expansion is an asymptotic, rather than a convergent, expansion.Comment: 9pp LaTeX; Talk at Telluride Workshop on Low Dimensional Field Theor

Self-Dual Chern-Simons Theories

In these lectures I review classical aspects of the self-dual Chern-Simons systems which describe charged scalar fields in $2+1$ dimensions coupled to a gauge field whose dynamics is provided by a pure Chern-Simons Lagrangian. These self-dual models have one realization with nonrelativistic dynamics for the scalar fields, and another with relativistic dynamics for the scalars. In each model, the energy density may be minimized by a Bogomol'nyi bound which is saturated by solutions to a set of first-order self-duality equations. In the nonrelativistic case the self-dual potential is quartic, the system possesses a dynamical conformal symmetry, and the self-dual solutions are equivalent to the static zero energy solutions of the equations of motion. The nonrelativistic self-duality equations are integrable and all finite charge solutions may be found. In the relativistic case the self-dual potential is sixth order and the self-dual Lagrangian may be embedded in a model with an extended supersymmetry. The self-dual potential has a rich structure of degenerate classical minima, and the vacuum masses generated by the Chern-Simons Higgs mechanism reflect the self-dual nature of the potential.Comment: 42 pages LaTe

The Irish Research electronic Library initiative – levelling the playing field?

Purpose - The Irish Research electronic Library (IReL) is a nationally funded electronic research library providing online access to full text articles from thousands of peer-reviewed publications in a range of disciplines. This paper examines the opportunities that have arisen for academic libraries at a local level in terms of how they expose resources and promote the initiative. It discusses the challenges that have arisen as libraries enhance, or indeed introduce, value added services to their research community. It examines the results of an in-depth national survey which yielded invaluable insights into how Irish researchers were using library services. Finally, it reflects on the challenges libraries face in facilitating and nurturing research behaviour. Design/methodology/approach – In the first quarter of 2007, seven university libraries asked their researchers for feedback on how they use IReL resources and their awareness of the initiative in the form of a national survey. These results and in particular the feedback from DCU researchers are further analysed. Focus groups and visits to research centres also provided more in-depth analysis. Findings- This paper finds that a collaborative approach to the negotiation of a single national licence for seven academic libraries, with associated training and a discount for consortium contracts has been highly successful. However, it has also posed significant challenges for all libraries in terms of ensuring that the resources are fully exploited and that the necessary support structures are in place to facilitate the provision of appropriate services to the growing research community. Originality/Value –This paper will be useful to libraries planning services for fourth level researchers and in particular, services that promote access to online resources

New relations between spinor and scalar one-loop effective Lagrangians in constant background fields

Simple new relations are presented between the one-loop effective Lagrangians of spinor and scalar particles in constant curvature background fields, both electromagentic and gravitational. These relations go beyond the well-known cases for self-dual background fields