7,853 research outputs found

    Equivariant Fields in an SU(N)SU({\cal N}) Gauge Theory with new Spontaneously Generated Fuzzy Extra Dimensions

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    We find new spontaneously generated fuzzy extra dimensions emerging from a certain deformation of N=4N=4 supersymmetric Yang-Mills (SYM) theory with cubic soft supersymmetry breaking and mass deformation terms. First, we determine a particular four dimensional fuzzy vacuum that may be expressed in terms of a direct sum of product of two fuzzy spheres, and denote it in short as SF2Int×SF2IntS_F^{2\, Int}\times S_F^{2\, Int}. The direct sum structure of the vacuum is revealed by a suitable splitting of the scalar fields in the model in a manner that generalizes our approach in \cite{Seckinson}. Fluctuations around this vacuum have the structure of gauge fields over SF2Int×SF2IntS_F^{2\, Int}\times S_F^{2\, Int}, and this enables us to conjecture the spontaneous broken model as an effective U(n)U(n) (n<N)(n < {\cal N}) gauge theory on the product manifold M4×SF2Int×SF2IntM^4 \times S_F^{2\, Int} \times S_F^{2\, Int}. We support this interpretation by examining the U(4)U(4) theory and determining all of the SU(2)×SU(2)SU(2)\times SU(2) equivariant fields in the model, characterizing its low energy degrees of freedom. Monopole sectors with winding numbers (±1,0),(0,±1),(±1,±1)(\pm 1,0),\,(0,\pm1),\,(\pm1,\pm 1) are accessed from SF2Int×SF2IntS_F^{2\, Int}\times S_F^{2\, Int} after suitable projections and subsequently equivariant fields in these sectors are obtained. We indicate how Abelian Higgs type models with vortex solutions emerge after dimensionally reducing over the fuzzy monopole sectors as well. A family of fuzzy vacua is determined by giving a systematic treatment for the splitting of the scalar fields and it is made manifest that suitable projections of these vacuum solutions yield all higher winding number fuzzy monopole sectors. We observe that the vacuum configuration SF2Int×SF2IntS_F^{2\, Int}\times S_F^{2\, Int} identifies with the bosonic part of the product of two fuzzy superspheres with OSP(2,2)×OSP(2,2)OSP(2,2)\times OSP(2,2) supersymmetry and elaborate on this feature.Comment: 38+1 pages, published versio

    Interaction of the vector-meson octet with the baryon octet in effective field theory

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    We analyze the constraint structure of the interaction of vector mesons with baryons using the classical Dirac constraint analysis. We show that the standard interaction in terms of two independent SU(3) structures is consistent at the classical level. We then require the self-consistency condition of the interacting system in terms of perturbative renormalizability to obtain relations for the renormalized coupling constants at the one-loop level. As a result we find a universal interaction with one coupling constant which is the same as in the massive Yang-Mills Lagrangian of the vector-meson sector.Comment: 18 pages, 1 figur

    SPATIAL ACCESSIBILITY OF HEALTH CARE IN INDIANA

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    Healthy populations and access to health care services are significant factors influencing economic development and prosperity. Since geographic access is an essential feature of an overall health system, it is important for health service researchers to develop accurate measures of physical access to health. In this paper we develop a series of gravity-based health care accessibility measures for all the counties in Indiana. The measures go beyond local availability of health care services within a county and account for travel impedance via distance-discounted health care services accessible throughout the state. When applied to Indiana counties, the results show sharp disparities in health care accessibility with extensive pockets of poor accessibility in rural and peripheral areas. The research concludes with a demonstration of how spatial accessibility measures can be beneficially used to evaluate of policies indicative of changes in the provision of health services.spatial accessibility, health care, geographic information systems (GIS),

    Population assessment of future trajectories in coronary heart disease mortality.

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    Background: Coronary heart disease (CHD) mortality rates have been decreasing in Iceland since the 1980s, largely reflecting improvements in cardiovascular risk factors. The purpose of this study was to predict future CHD mortality in Iceland based on potential risk factor trends. Methods and findings: The previously validated IMPACT model was used to predict changes in CHD mortality between 2010 and 2040 among the projected population of Iceland aged 25–74. Calculations were based on combining: i) data on population numbers and projections (Statistics Iceland), ii) population risk factor levels and projections (Refine Reykjavik study), and iii) effectiveness of specific risk factor reductions (published meta-analyses). Projections for three contrasting scenarios were compared: 1) If the historical risk factor trends of past 30 years were to continue, the declining death rates of past decades would level off, reflecting population ageing. 2) If recent trends in risk factors (past 5 years) continue, this would result in a death rate increasing from 49 to 70 per 100,000. This would reflect a recent plateau in previously falling cholesterol levels and recent rapid increases in obesity and diabetes prevalence. 3) Assuming that in 2040 the entire population enjoys optimal risk factor levels observed in low risk cohorts, this would prevent almost all premature CHD deaths before 2040. Conclusions: The potential increase in CHD deaths with recent trends in risk factor levels is alarming both for Iceland and probably for comparable Western populations. However, our results show considerable room for reducing CHD mortality. Achieving the best case scenario could eradicate premature CHD deaths by 2040. Public health policy interventions based on these predictions may provide a cost effective means of reducing CHD mortality in the future

    Digitization of LAr calorimeter for CSC simulations

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    This note describes the digitization of the LAr signals, which is the step creating RDO from Geant4 Hits, as used during the production of the CSC simulated samples with athena release 12

    Fast and Highly Sensitive Ionic-Polymer-Gated WS2 -Graphene Photodetectors

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    This is the final version of the article. Available from Wiley via the DOI in this record.The combination of graphene with semiconductor materials in heterostructure photodetectors enables amplified detection of femtowatt light signals using micrometer-scale electronic devices. Presently, long-lived charge traps limit the speed of such detectors, and impractical strategies, e.g., the use of large gate-voltage pulses, have been employed to achieve bandwidths suitable for applications such as video-frame-rate imaging. Here, atomically thin graphene-WS2 heterostructure photodetectors encapsulated in an ionic polymer are reported, which are uniquely able to operate at bandwidths up to 1.5 kHz whilst maintaining internal gain as large as 10(6) . Highly mobile ions and the nanometer-scale Debye length of the ionic polymer are used to screen charge traps and tune the Fermi level of the graphene over an unprecedented range at the interface with WS2 . Responsivity R = 10(6) A W(-1) and detectivity D* = 3.8 × 10(11) Jones are observed, approaching that of single-photon counters. The combination of both high responsivity and fast response times makes these photodetectors suitable for video-frame-rate imaging applications.J.D.M. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1 ). S.F.R acknowledges financial support from the Higher Committee for Education Development in Iraq (HCED). S.R. and M.F.C. acknowledge financial support from EPSRC (Grant No. EP/J000396/1, EP/K017160/1, EP/K010050/1, EP/G036101/1, EP/M001024/1, and EP/M002438/1) and from Royal Society International Exchanges Scheme 2016/R1

    Comparison of PI Controllers Designed for the Delay Model of TCP/AQM Networks

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    Cataloged from PDF version of article.One of the major problems of communication networks is congestion. In order to address this problem in TCP/IP networks, Active Queue Management (AQM) scheme is recommended. AQM aims to minimize the congestion by regulating the average queue size at the routers. To improve upon AQM, recently, several feedback control approaches were proposed. Among these approaches, PI controllers are gaining attention because of their simplicity and ease of implementation. In this paper, by utilizing the fluid-flow model of TCP networks, we study the PI controllers designed for TCP/AQM. We compare these controllers by first analyzing their robustness and fragility. Then, we implement these controllers in ns-2 platform and conduct simulation experiments to compare their performances in terms of queue length. Taken together, our results provide a guideline for choosing a PI controller for AQM given specific performance requirements. (C) 2013 Elsevier B.V. All rights reserved

    Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop

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    Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases. However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to generate evidence-based policy, and they encourage further evaluation of this approach
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