911 research outputs found

    Minimization via duality

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    We show how to use duality theory to construct minimized versions of a wide class of automata. We work out three cases in detail: (a variant of) ordinary automata, weighted automata and probabilistic automata. The basic idea is that instead of constructing a maximal quotient we go to the dual and look for a minimal subalgebra and then return to the original category. Duality ensures that the minimal subobject becomes the maximally quotiented object

    Can a Measurement of the Bs−B‟sB_{s} - {\overline{B}}_{s} Mass Difference Establish the CKM Paradigm?

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    We present a reanalysis of the allowed region in the ρ−η \rho - \eta \, plane of the CKM matrix, which follows from our present knowledge of the theoretical and experimental parameters associated with quark mixing and CP violation. Besides providing updated expectations for the angles of the unitarity triangle, this reanalysis predicts a range of allowed values for the Bs−B‟s B_{s} - {\overline{B}}_{s} \, mass difference Δms\Delta m_{s}. We argue that while values of \Delta m_{s} \lsim 10 (ps)^{-1} could be consistent with a non-CKM origin for CP violation in the neutral Kaon system, larger values for Δms\Delta m_{s} would provide strong support for the CKM paradigm.Comment: 9 pages, LaTex, 3 uuencoded eps figures(embedded with epsfig.sty)

    Capitals and commitment. The case of a local learning and employment network.

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    This article draws on research undertaken with a Local Learning and Employment Network (LLEN) in the state of Victoria, Australia. LLEN are networks that were implemented by the state government in 2001 to undertake community capacity building through which the outcomes of young people aged 15-19 in education, training and employment would be enhanced. In 2008, in the context of an enhanced federal commitment to social inclusion through ‘joining-up’, the Victorian experience provides insights on the implications of such policy initiatives. Drawing on Bourdieu’s discussion of the forms of capital and Granovetter’s notion of the strength of weak ties, I argue that stores of economic, cultural and social capital as outlined by Bourdieu were necessary, but insufficient, for LLEN to achieve the objectives with which they were charged given the failure of government to follow through on the implications of its policies. I argue for a commitment on the part of all stakeholders to realise the potential of ‘joining-up’

    The Reporting on ERAS Compliance, Outcomes, and Elements Research (RECOvER) Checklist: A Joint Statement by the ERAS<sup>Âź</sup> and ERAS<sup>Âź</sup> USA Societies.

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    Enhanced recovery after surgery (ERAS) programs are multimodal care pathways designed to minimize the physiological and psychological impact of surgery for patients. Increased compliance with ERAS guidelines is associated with improved patient outcomes across surgical types. As ERAS programs have proliferated, an unintentional effect has been significant variation in how ERAS-related studies are reported in the literature. To improve the quality of ERAS reporting, ERAS &lt;sup&gt;Âź&lt;/sup&gt; USA and the ERAS &lt;sup&gt;Âź&lt;/sup&gt; Society launched an effort to create an instrument to assist authors in manuscript preparation. Criteria to include were selected by a combination of literature review and expert opinion. The final checklist was refined by group consensus. The Societies present the Reporting on ERAS Compliance, Outcomes, and Elements Research (RECOvER) Checklist. The tool contains 20 items including best practices for reporting clinical pathways, compliance auditing, and formatting guidelines. The RECOvER Checklist is intended to provide a standardized framework for the reporting of ERAS-related studies. The checklist can also assist reviewers in evaluating the quality of ERAS-related manuscripts. Authors are encouraged to include the RECOvER Checklist when submitting ERAS-related studies to peer-reviewed journals

    Vertically Self-Gravitating ADAFs in the Presence of Toroidal Magnetic Field

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    Force due to the self-gravity of the disc in the vertical direction is considered to study its possible effects on the structure of a magnetized advection-dominated accretion disc. We present steady-sate self similar solutions for the dynamical structure of such a type of the accretion flows. Our solutions imply reduced thickness of the disc because of the self-gravity. It also imply that the thickness of the disc will increase by adding the magnetic field strength.Comment: Accepted for publication in Astrophysics and Space Science

    Quantum phase transitions from topology in momentum space

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    Many quantum condensed matter systems are strongly correlated and strongly interacting fermionic systems, which cannot be treated perturbatively. However, physics which emerges in the low-energy corner does not depend on the complicated details of the system and is relatively simple. It is determined by the nodes in the fermionic spectrum, which are protected by topology in momentum space (in some cases, in combination with the vacuum symmetry). Close to the nodes the behavior of the system becomes universal; and the universality classes are determined by the toplogical invariants in momentum space. When one changes the parameters of the system, the transitions are expected to occur between the vacua with the same symmetry but which belong to different universality classes. Different types of quantum phase transitions governed by topology in momentum space are discussed in this Chapter. They involve Fermi surfaces, Fermi points, Fermi lines, and also the topological transitions between the fully gapped states. The consideration based on the momentum space topology of the Green's function is general and is applicable to the vacua of relativistic quantum fields. This is illustrated by the possible quantum phase transition governed by topology of nodes in the spectrum of elementary particles of Standard Model.Comment: 45 pages, 17 figures, 83 references, Chapter for the book "Quantum Simulations via Analogues: From Phase Transitions to Black Holes", to appear in Springer lecture notes in physics (LNP

    Computational Physics on Graphics Processing Units

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    The use of graphics processing units for scientific computations is an emerging strategy that can significantly speed up various different algorithms. In this review, we discuss advances made in the field of computational physics, focusing on classical molecular dynamics, and on quantum simulations for electronic structure calculations using the density functional theory, wave function techniques, and quantum field theory.Comment: Proceedings of the 11th International Conference, PARA 2012, Helsinki, Finland, June 10-13, 201

    Field-Induced Magnetic Ordering in the Quantum Spin System KCuCl3_3

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    KCuCl3_3 is a three-dimensional coupled spin-dimer system and has a singlet ground state with an excitation gap Δ/kB=31{\Delta}/k_{\rm B}=31 K. High-field magnetization measurements for KCuCl3_3 have been performed in static magnetic fields of up to 30 T and in pulsed magnetic fields of up to 60 T. The entire magnetization curve including the saturation region was obtained at T=1.3T=1.3 K. From the analysis of the magnetization curve, it was found that the exchange parameters determined from the dispersion relations of the magnetic excitations should be reduced, which suggests the importance of the renormalization effect in the magnetic excitations. The field-induced magnetic ordering accompanied by the cusplike minimum of the magnetization was observed as in the isomorphous compound TlCuCl3_3. The phase boundary was almost independent of the field direction, and is represented by the power law. These results are consistent with the magnon Bose-Einstein condensation picture for field-induced magnetic ordering.Comment: 9 pages, 7 figures, 9 eps files, revtex styl

    Low-Luminosity Accretion in Black Hole X-ray Binaries and Active Galactic Nuclei

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    At luminosities below a few percent of Eddington, accreting black holes switch to a hard spectral state which is very different from the soft blackbody-like spectral state that is found at higher luminosities. The hard state is well-described by a two-temperature, optically thin, geometrically thick, advection-dominated accretion flow (ADAF) in which the ions are extremely hot (up to 101210^{12} K near the black hole), the electrons are also hot (∌109−10.5\sim10^{9-10.5} K), and thermal Comptonization dominates the X-ray emission. The radiative efficiency of an ADAF decreases rapidly with decreasing mass accretion rate, becoming extremely low when a source reaches quiescence. ADAFs are expected to have strong outflows, which may explain why relativistic jets are often inferred from the radio emission of these sources. It has been suggested that most of the X-ray emission also comes from a jet, but this is less well established.Comment: To appear in "From X-ray Binaries to Quasars: Black Hole Accretion on All Mass Scales" edited by T. Maccarone, R. Fender, L. Ho, to be published as a special edition of "Astrophysics and Space Science" by Kluwe
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