Electrically and Magnetically Charged States and Particles in the 2+1-Dimensional Z_N-Higgs Gauge Model

Electrically as well as magnetically charged states are constructed in the 2+1-dimensional Euclidean Z_N-Higgs lattice gauge model, the former following ideas of Fredenhagen and Marcu and the latter using duality transformations on the algebra of observables. The existence of electrically and of magnetically charged particles is also established. With this work we prepare the ground for the constructive study of anyonic statistics of multiparticle scattering states of electrically and magnetically charged particles in this model (work in progress).Comment: 57 pages, Sfb 288 Preprint No. 109. To appear in Commun. Math. Phys. About the file: This is a uuencoded, "gzip-ed" postscript file. It is about 300kB large. The original ps file is about 700kB large. All figures are included. The LaTeX sources ou even hard copies can be required to the authors at [email protected] or Freie Universitaet Berlin. Institut fuer Theoretische Physik. Arnimallee 14. Berlin 14195 German

Localizability in de Sitter space

An analogue of the Newton-Wigner position operator is defined for a massive neutral scalar field in de Sitter space. The one-particle subspace of the theory, consisting of positive-energy solutions of the Klein-Gordon equation selected by the Hadamard condition, is identified with an irreducible representation of de Sitter group. Postulates of localizability analogous to those written by Wightman for fields in Minkowski space are formulated on it, and a unique solution is shown to exist. A simple expression for the time-evolution of the operator is presented.Comment: Presentation improved; references adde

Abused women\u27s perspectives on the criminal justice system\u27s response to domestic violence.

In the last five years a number of studies have been conducted that have given abused women voice in the discussion about whether or not the criminal justice system (CJS) can be helpful to them. These studies have used a variety of methods and examined different questions, but they have not considered how women\u27s views of separate parts of the CJS come together in their perspectives about the system as a whole. The purpose of this study was to better understand battered women\u27s views about the criminal justice system (CJS), and how those views are integrated into complex perspectives for individual women. Q methodology was used. Fifty-eight abused and formally abused women were recruited to represent a broad range of experiences and perspectives. They sorted 72 statements about domestic violence and the CJS on a large template that ranged from strongly disagree to strongly agree. Principal component analysis with varimax rotation was performed and the resulting factors were analysed for meaning. A small number of women who represented each factor were interviewed to aid in this interpretation. Five perspectives were identified representing divergent views of the CJS: (1) Trust in the CJS; (2) Disappointment in the CJS; (3) Victims should have input into the CJS and be sure they want to use it; (4) The CJS cannot protect women and can make matters worse; and (5) The CJS should be used for her safety, for his rehabilitation, and for justice despite its problems. The perspectives that emerged are new in their complexity and in their substance. Overall, the emergence of multiple perspectives as opposed to one polarized perspective has theoretical, methodological, and applied implications for research and practice. The description of each of the perspectives expressed by the women in this study may also be useful in advising other women who hold similar perspectives.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .B37. Source: Dissertation Abstracts International, Volume: 65-07, Section: B, page: 3770. Adviser: Charlene Senn. Thesis (Ph.D.)--University of Windsor (Canada), 2004

The Two-Point Function and the Effective Magnetic Field in Diluted Ising Models on the Cayley Tree

Some results on the two-point function and on the analytic structure of the momenta of the effective fugacity at the origin for a class of diluted ferromagnetic Ising models on the Cayley tree are presented.Comment: 22 page

Aspects of Two-Level Systems under External Time Dependent Fields

The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman, Vernon and Hellwarth, we discuss in detail the possibility to reduce the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility to directly apply powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for ``quantum chaos'' when the external background is periodic or quasi-periodic in time.Comment: To appear in J. Phys. A. Mathematical and Genera

Multiple classical limits in relativistic and nonrelativistic quantum mechanics

The existence of a classical limit describing interacting particles in a second-quantized theory of identical particles with bosonic symmetry is proved. This limit exists in addition to a previously established classical limit with a classical field behavior, showing that the limit $\hbar \to 0$ of the theory is not unique. An analogous result is valid for a free massive scalar field: two distinct classical limits are proved to exist, describing a system of particles or a classical field. The introduction of local operators in order to represent kinematical properties of interest is shown to break the permutation symmetry under some localizability conditions, allowing the study of individual particle properties.Comment: 13 page

Converging Perturbative Solutions of the Schroedinger Equation for a Two-Level System with a Hamiltonian Depending Periodically on Time

We study the Schroedinger equation of a class of two-level systems under the action of a periodic time-dependent external field in the situation where the energy difference 2epsilon between the free energy levels is sufficiently small with respect to the strength of the external interaction. Under suitable conditions we show that this equation has a solution in terms of converging power series expansions in epsilon. In contrast to other expansion methods, like in the Dyson expansion, the method we present is not plagued by the presence of ``secular terms''. Due to this feature we were able to prove absolute and uniform convergence of the Fourier series involved in the computation of the wave functions and to prove absolute convergence of the epsilon-expansions leading to the ``secular frequency'' and to the coefficients of the Fourier expansion of the wave function