Electroweak Symmetry Breaking From Monopole Condensation

We examine models where massless chiral fermions with both "electric" and "magnetic" hypercharges could form condensates. When some of the fermions are also electroweak doublets such condensates can break the electroweak gauge symmetry down to electromagnetism in the correct way. Since ordinary hypercharge is weakly coupled at the TeV scale, magnetic hypercharge is strongly coupled and can potentially drive the condensation. Such models are similar to technicolor, but with hypercharge playing the role of the technicolor gauge group, so the standard model gauge group breaks itself. A heavy top mass can be generated via the Rubakov-Callan effect and could thus decouple the scale of flavor physics from the electroweak scale.Comment: Absence of pseudo-Goldstone bosons explain, discussion of the role of flavor physics clarified, other minor changes. References adde

On the Rate-dependent Plasticity Modelling of Unidirectional Fibre-reinforced Polymeric Matrix Composites

Three different approaches to plasticity are investigated to model the experimentally-observed non-linear behaviour of unidirectional fibre-reinforced polymeric matrix materials. The first and simplest approach consists on assuming independent one-dimensional rate-dependent plasticity on in-plane (12) and through-thickness longitudinal (13) shear components of the Cauchy stress tensor. The second, employs a 3D extension of the plane stress Hill'48 anisotropic plastic surface. The third and the last is formulated as a quadratic yield function inspired by Puck's fracture initiation criterion. It searches for a plastic localisation plane in which a certain combination of normal and shear stresses is maximum. Numerical simulations are conducted to analyse the off-axis compression behaviour of carbon fibre reinforced epoxy composite under varying loading rates. The afore-mentioned three different approaches are explored with an aim to predict the experimentally-observed non-linear response of such composites. The model parameters are determined using a deterministic inverse modelling strategy employing an iterative domain reduction optimisation technique. As far as the experiments are concerned, the quasi-static and medium rate tests were carried out in universal testing machines, while the experiments at high rate were conducted in a Split Hopkinson Pressure Bar system. The effectiveness in terms of accuracy and robustness of the three approaches are discussed

A note about the ground state of the H3+{\rm H}_3^+ hydrogen molecular ion

Three simple $7-, (7+3)-, 10-$parametric trial functions for the ${\rm H}_3^+$ molecular ion are presented. Each of them provides subsequently the most accurate approximation for the Born-Oppenheimer ground state energy among several-parametric trial functions. These trial functions are chosen following a criterion of physical adequacy and includes the electronic correlation in the exponential form $\sim\exp{(\gamma r_{12})}$, where $\gamma$ is a variational parameter. The Born-Oppenheimer energy is found to be $E=-1.340 34, -1.340 73, -1.341 59$\,a.u., respectively, for optimal equilateral triangular configuration of protons with the equilibrium interproton distance $R=1.65$\,a.u. The variational energy agrees in three significant digits (s.d.) with most accurate results available at present as well as for major expectation values.Comment: 12 pages, 1 figure, 3 table

Sacred Spheres: Religious Autonomy As An International Human Right

How should courts resolve thorny human rights disputes that arise within religious groups? According to an emerging international consensus, they shouldn’t. When a case involves sensitive internal decisions by a religious organization, such as choosing who is qualified to teach the faith, courts are increasingly taking a hands-off approach. This global consensus has formed across international treaties, tribunals, and domestic courts in European and American nations. Every major human rights instrument and many international and domestic courts recognize that religious freedom must extend to religious communities, especially houses of worship and schools where believers gather to practice their faith and impart it to the next generation. This article conducts a comparative analysis of religious autonomy across international human rights instruments, international courts, and a selection of individual countries. We argue that the autonomy of religious institutions is an internationally recognized principle that protects decisions related to internal religious governance, including who teaches the faith to the next generation. To allow secular governments to dictate who teaches the faith and how it is taught in spheres explicitly governed by church leaders would violate that religious autonomy. Instead, we urge international courts to provide clarity and guidance to countries seeking to apply thereligious freedom provisions in their own laws by respecting the ability of religious organizations to govern who teaches their doctrines. The recent case of Pavez v. Chile at the Inter-American Court of Human Rights provides a counter-example to the growing consensus. There, the court found Chile liable for discrimination when it respected a local church decision regarding who was qualified to teach Catholicism to students in a devotional setting in a state-run school. Rather than engage with the reasoning of the international law on church autonomy, the court acknowledged this body of law, but declined to apply it in the case, maintaining that the state should retain authority over the church in who teaches the faith. In so doing, the Court attempts to force the separate spheres of church and state to merge, asserting control over the church and its relationship with the government. Without a well-reasoned theory behind this attempt, however, it is unlikely to be repeated in other serious adjudicative bodies

Recognition versus Disclosure: An Investigation of the Impact on Equity Risk Using UK Operating Lease Disclosures

This study examines the equivalency of accounting recognition versus disclosure. OLS regression analysis is used to determine whether there is an association between equity risk and an adjustment to financial risk for off-balance sheet operating leases. Two methods of adjustment are considered: constructive capitalisation and a simple factor method. The observation of a reliably positive association suggests that UK investors/analysts view operating leases from a property rights perspective rather than an ownership perspective. This supports the argument for recognition of all lease rights and obligations 'on-balance sheet', as proposed in the recent G4+1 discussion paper ASB (1999)

In vitro osteogenic differentiation of human ES cells

Since their isolation in 1998, human embryonic stem (hES) cells have been shown to be capable of adopting various cell fates in vitro. Here, we present in vitro data demonstrating the directed commitment of human embryonic stem cells to the osteogenic lineage. Human ES cells are shown to respond to factors that promote osteogenesis, leading to activation of the osteogenic markers osteocalcin, parathyroid hormone receptor, bone sialoprotein, osteopontin, cbfa1, and collagen 1. Moreover, the mineralized nodules obtained are composed of hydroxyapatite, further establishing the similarity of osteoblasts in culture to bone. These results show that osteoblasts can be derived from human ES cultures in vitro and provide the basis for comparison of adult and embryonic-derived osteogenesis, and for an investigation of potential applications for hES cells in orthopaedic tissue repair

Experimental approaches for 100 TeV gamma-ray astronomy

The high energy end of gamma-ray source spectra might provide important clues regarding the nature of the processes involved in gamma-ray emission. Several galactic sources with hard emission spectra extending up to more than 30TeV have already been reported. Measurements around 100TeV and above should be an important goal for the next generation of high energy gamma-ray astronomy experiments. Here we present several techniques providing the required exposure (100 km^2.h). We focus our study on three Imaging Atmospheric Cherenkov Technique (IACT) based approaches: low elevation observations, large field of view telescopes, and large telescope arrays. We comment on the advantages and disadvantages of each approach and report simulation based estimates of their energy ranges and sensitivities.Comment: 3 pages 1 figure. Proceedings of TeV particle astrophysics 2, Madison, August 2006. http://www.icecube.wisc.edu/TeV/presentations/colin_poster.pd

Electronic structure of fully epitaxial Co2TiSn thin films

In this article we report on the properties of thin films of the full Heusler compound Co2TiSn prepared by DC magnetron co-sputtering. Fully epitaxial, stoichiometric films were obtained by deposition on MgO (001) substrates at substrate temperatures above 600{\deg}C. The films are well ordered in the L21 structure, and the Curie temperature exceeds slightly the bulk value. They show a significant, isotropic magnetoresistance and the resistivity becomes strongly anomalous in the paramagnetic state. The films are weakly ferrimagnetic, with nearly 1 \mu_B on the Co atoms, and a small antiparallel Ti moment, in agreement with theoretical expectations. From comparison of x-ray absorption spectra on the Co L3/L2 edges, including circular and linear magnetic dichroism, with ab initio calculations of the x-ray absorption and circular dichroism spectra we infer that the electronic structure of Co2TiSn has essentially non-localized character. Spectral features that have not been explained in detail before, are explained here in terms of the final state band structure.Comment: 11 pages, 8 figure

Superconducting fluctuations at low temperature

The effect of fluctuations on the transport and thermodynamic properties of two-dimensional superconductors in a magnetic field is studied at low temperature. The fluctuation conductivity is calculated in the framework of the perturbation theory with the help of usual diagram technique. It is shown that in the dirty case the Aslamazov-Larkin, Maki-Thomson and Density of States contributions are of the same order. At extremely low temperature, the total fluctuation correction to the normal conductivity is negative in the dirty limit and depends on the external magnetic field logarithmically. In the non-local clean limit, the Aslamazov-Larkin contribution to conductivity is evaluated with the aid of the Helfand-Werthamer theory. The longitudinal and Hall conductivities are found. The fluctuating magnetization is calculated in the one-loop and two-loop approximations.Comment: 12 pages, 4 figures, submitted to Phys. Rev.