29,750 research outputs found

    Party finance reform as constitutional engineering? The effectiveness and unintended consequences of party finance reform in France and Britain

    Get PDF
    In both Britain and France, party funding was traditionally characterized by a laissez faire approach and a conspicuous lack of regulation. In France, this was tantamount to a 'legislative vacuum'. In the last two decades, however, both countries have sought to fundamentally reform their political finance regulation regimes. This prompted, in Britain, the Political Parties, Elections and Referendums Act 2000, and in France a bout of 'legislative incontinence' — profoundly transforming the political finance regime between 1988 and 1995. This article seeks to explore and compare the impacts of the reforms in each country in a bid to explain the unintended consequences of the alternative paths taken and the effectiveness of the new party finance regime in each country. It finds that constitutional engineering through party finance reform is a singularly inexact science, largely due to the imperfect nature of information, the limited predictability of cause and effect, and the constraining influence of non-party actors, such as the Constitutional Council in France, and the Electoral Commission in Britain

    Configuration-Space Location of the Entanglement between Two Subsystems

    Full text link
    In this paper we address the question: where in configuration space is the entanglement between two particles located? We present a thought-experiment, equally applicable to discrete or continuous-variable systems, in which one or both parties makes a preliminary measurement of the state with only enough resolution to determine whether or not the particle resides in a chosen region, before attempting to make use of the entanglement. We argue that this provides an operational answer to the question of how much entanglement was originally located within the chosen region. We illustrate the approach in a spin system, and also in a pair of coupled harmonic oscillators. Our approach is particularly simple to implement for pure states, since in this case the sub-ensemble in which the system is definitely located in the restricted region after the measurement is also pure, and hence its entanglement can be simply characterised by the entropy of the reduced density operators. For our spin example we present results showing how the entanglement varies as a function of the parameters of the initial state; for the continuous case, we find also how it depends on the location and size of the chosen regions. Hence we show that the distribution of entanglement is very different from the distribution of the classical correlations.Comment: RevTex, 12 pages, 9 figures (28 files). Modifications in response to journal referee

    Long period polytype boundaries in silicon carbide

    Get PDF
    A significant gap in our understanding of polytypism exists, caused partly by the lack of experimental data on the spatial distribution of polytype coalescence and knowledge of the regions between adjoining polytypes. Few observations, Takei & Francombe (1967) apart, of the relative location of different polytypes have been reported. A phenomenological description of the boundaries, exact position of one-dimensional disorder (1DD) and long period polytypes (LPP’s) has been made possible by synchrotron X-ray diffraction topography (XRDT)

    Maximum-Likelihood Comparisons of Tully-Fisher and Redshift Data: Constraints on Omega and Biasing

    Full text link
    We compare Tully-Fisher (TF) data for 838 galaxies within cz=3000 km/sec from the Mark III catalog to the peculiar velocity and density fields predicted from the 1.2 Jy IRAS redshift survey. Our goal is to test the relation between the galaxy density and velocity fields predicted by gravitational instability theory and linear biasing, and thereby to estimate βI=Ω0.6/bI,\beta_I = \Omega^{0.6}/b_I, where bIb_I is the linear bias parameter for IRAS galaxies. Adopting the IRAS velocity and density fields as a prior model, we maximize the likelihood of the raw TF observables, taking into account the full range of selection effects and properly treating triple-valued zones in the redshift-distance relation. Extensive tests with realistic simulated galaxy catalogs demonstrate that the method produces unbiased estimates of βI\beta_I and its error. When we apply the method to the real data, we model the presence of a small but significant velocity quadrupole residual (~3.3% of Hubble flow), which we argue is due to density fluctuations incompletely sampled by IRAS. The method then yields a maximum likelihood estimate βI=0.49±0.07\beta_I=0.49\pm 0.07 (1-sigma error). We discuss the constraints on Ω\Omega and biasing that follow if we assume a COBE-normalized CDM power spectrum. Our model also yields the 1-D noise noise in the velocity field, including IRAS prediction errors, which we find to be be 125 +/- 20 km/sec.Comment: 53 pages, 20 encapsulated figures, two tables. Submitted to the Astrophysical Journal. Also available at http://astro.stanford.edu/jeff

    Series Analysis of Tricritical Behavior: Mean-Field Model and Slicewise Pade Approximants

    Full text link
    A mean-field model is proposed as a test case for tricritical series analyses methods. Derivation of the 50th order series for the magnetization is reported. As the first application this series is analyzed by the traditional slicewise Pade approximant method popular in earlier studies of tricriticality.Comment: 22 pages in plain TeX; 7 PostScript figs available by e-mai

    Resistive Anomalies at Ferromagnetic Transitions Revisited: the case of SrRuO_3

    Full text link
    We show that recent resistivity data on SrRuO_3 for T->T_c are consistent with conventional theory when corrections to scaling are included and a small shift in T_c is allowed.Comment: 2 pages, 1 figure; revte

    Edwards-Wilkinson surface over a spherical substrate: 1/f1/f noise in the height fluctuations

    Full text link
    We study the steady state fluctuations of an Edwards-Wilkinson type surface with the substrate taken to be a sphere. We show that the height fluctuations on circles at a given latitude has the effective action of a perfect Gaussian 1/f1/f noise, just as in the case of fixed radius circles on an infinite planar substrate. The effective surface tension, which is the overall coefficient of the action, does not depend on the latitude angle of the circles.Comment: 6 page
    • …
    corecore