6,828 research outputs found

    A Unified Elementary Approach to the Dyson, Morris, Aomoto, and Forrester Constant Term Identities

    Get PDF
    We introduce an elementary method to give unified proofs of the Dyson, Morris, and Aomoto identities for constant terms of Laurent polynomials. These identities can be expressed as equalities of polynomials and thus can be proved by verifying them for sufficiently many values, usually at negative integers where they vanish. Our method also proves some special cases of the Forrester conjecture.Comment: 20 page

    Lepton flavor violating signals of the neutral top-pion in future lepton colliders

    Full text link
    The presence of the top-pions πt0,±\pi_{t}^{0,\pm} in the low-energy spectrum is an inevitable feature of the topcolor scenario. Taking into account the constraints of the present experimental limit of the lepton flavor violating(LFVLFV) process μeγ\mu\to e\gamma on the free parameters of topcolor-assisted techicolor(TC2) models, we study the contributions of the neutral top-pion πt0\pi^{0}_{t} to the LFVLFV processes μ+μτμ\mu^{+}\mu^{-}\to\tau \mu (or τe\tau e), γγτμ \gamma \gamma\to\tau \mu (or τe\tau e), e+eτμe^{+} e^{-}\to\tau \mu , and eγeπt0eτμ(e)e \gamma\to e \pi_{t}^{0}\to e \tau \mu(e) via the flavor changing (FCFC) couplings πt0lilj\pi_{t}^{0}l_{i}l_{j} and discuss the possibility of searching for the LFVLFV signals via these processes in future lepton colliders.Comment: References added, some typos corrected. Version to be published in Phys. Rev.

    Offshoring Pollution while Offshoring Production?

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138846/1/smj2656.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138846/2/smj2656_am.pd

    Numerical Simulation Based Targeting of the Magushan Skarn Cu-Mo Deposit, Middle-Lower Yangtze Metallogenic Belt, China

    Get PDF
    The Magushan Cu–Mo deposit is a skarn deposit within the Nanling–Xuancheng mining district of the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB), China. This study presents the results of a new numerical simulation that models the ore-forming processes that generated the Magushan deposit and enables the identification of unexplored areas that have significant exploration potential under areas covered by thick sedimentary sequences that cannot be easily explored using traditional methods. This study outlines the practical value of numerical simulation in determining the processes that operate during mineral deposit formation and how this knowledge can be used to enhance exploration targeting in areas of known mineralization. Our simulation also links multiple subdisciplines such as heat transfer, pressure, fluid flow, chemical reactions, and material migration. Our simulation allows the modeling of the formation and distribution of garnet, a gangue mineral commonly found within skarn deposits (including within the Magushan deposit). The modeled distribution of garnet matches the distribution of known mineralization as well as delineating areas that may well contain high garnet abundances within and around a concealed intrusion, indicating this area should be considered a prospective target during future mineral exploration. Overall, our study indicates that this type of numerical simulation-based approach to prospectivity modeling is both effective and economical and should be considered an additional tool for future mineral exploration to reduce exploration risks when targeting mineralization in areas with thick and unprospective sedimentary cover sequences

    Effect of Peierls transition in armchair carbon nanotube on dynamical behaviour of encapsulated fullerene

    Get PDF
    The changes of dynamical behaviour of a single fullerene molecule inside an armchair carbon nanotube caused by the structural Peierls transition in the nanotube are considered. The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory. Significant changes of the barriers for motion along the nanotube axis and rotation of these fullerenes inside the (8,8) nanotube are found at the Peierls transition. It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude. The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.Comment: 9 pages, 6 figures, 1 tabl

    The swap operation in the two-qubit Heisenberg XXZ model-effects of anisotropy and magnetic field

    Full text link
    In this paper we study the swap operation in a two-qubit anisotropic XXZ model in the presence of an inhomogeneous magnetic field. We establish the range of anisotropic parameter within which the swap operation is feasible. The swap errors caused by the inhomogeneous field are evaluated

    Modelling and control of the flame temperature distribution using probability density function shaping

    Get PDF
    This paper presents three control algorithms for the output probability density function (PDF) control of the 2D and 3D flame distribution systems. For the 2D flame distribution systems, control methods for both static and dynamic flame systems are presented, where at first the temperature distribution of the gas jet flames along the cross-section is approximated. Then the flame energy distribution (FED) is obtained as the output to be controlled by using a B-spline expansion technique. The general static output PDF control algorithm is used in the 2D static flame system, where the dynamic system consists of a static temperature model of gas jet flames and a second-order actuator. This leads to a second-order closed-loop system, where a singular state space model is used to describe the dynamics with the weights of the B-spline functions as the state variables. Finally, a predictive control algorithm is designed for such an output PDF system. For the 3D flame distribution systems, all the temperature values of the flames are firstly mapped into one temperature plane, and the shape of the temperature distribution on this plane can then be controlled by the 3D flame control method proposed in this paper. Three cases are studied for the proposed control methods and desired simulation results have been obtained

    Production and decay of the neutral top-pion in high energy e+ee^{+}e^{-} colliders

    Full text link
    We study the production and decay of the neutral top-pion πt0\pi_{t}^{0} predicted by topcolor-assisted technicolor(TC2) theory. Our results show that, except the dominant decay modes bbˉb\bar{b}, tˉc\bar{t}c and gggg, the πt0\pi_{t}^{0} can also decay into γγ\gamma\gamma and ZγZ \gamma modes. It can be significantly produced at high energy e+ee^{+}e^{-} collider(LC) experiments via the processes e+eπt0γe^{+}e^{-}\to \pi_{t}^{0}\gamma and e+eZπt0e^{+}e^{-}\to Z\pi_{t}^{0}. We further calculate the production cross sections of the processes e+eγπt0γtˉce^{+}e^{-}\to\gamma\pi_{t}^{0}\to\gamma\bar{t}c and e+eZπt0Ztˉce^{+}e^{-}\to Z\pi_{t}^{0}\to Z\bar{t}c. We find that the signatures of the neutral top-pion πt0\pi_{t}^{0} can be detected via these processes.Comment: Latex file, 13 Pages, 6 eps figures. to be published in Phys.Rev.

    Leptin-Receptor-Expressing Mesenchymal Stromal Cells Represent the Main Source of Bone Formed by Adult Bone Marrow

    Get PDF
    SummaryStudies of the identity and physiological function of mesenchymal stromal cells (MSCs) have been hampered by a lack of markers that permit both prospective identification and fate mapping in vivo. We found that Leptin Receptor (LepR) is a marker that highly enriches bone marrow MSCs. Approximately 0.3% of bone marrow cells were LepR+, 10% of which were CFU-Fs, accounting for 94% of bone marrow CFU-Fs. LepR+ cells formed bone, cartilage, and adipocytes in culture and upon transplantation in vivo. LepR+ cells were Scf-GFP+, Cxcl12-DsRedhigh, and Nestin-GFPlow, markers which also highly enriched CFU-Fs, but negative for Nestin-CreER and NG2-CreER, markers which were unlikely to be found in CFU-Fs. Fate-mapping showed that LepR+ cells arose postnatally and gave rise to most bone and adipocytes formed in adult bone marrow, including bone regenerated after irradiation or fracture. LepR+ cells were quiescent, but they proliferated after injury. Therefore, LepR+ cells are the major source of bone and adipocytes in adult bone marrow

    Visualization Support for Cognitive Sciences

    Get PDF
    The science of computer graphics and visualization is intertwined in many ways with Cognitive Sciences. On the one hand, computer graphics can lead to virtual environments in which a person is exposed to a virtual scenario. Typically, 3D-capable display technology combined with tracking systems, which are capable of identifying where the person is located at, are deployed to achieve maximal immersion in that the persons point of view is recreated in the virtual scenario. As a result, an impressive experience is created such that that person is navigating the virtual scenario as if it was real. On the other hand, visualization techniques can be utilized to present the results from a cognitive science experiment to the user such that it provides easier access to the data. This could range from simple plots to more sophisiticated approaches, such as parallel coordinates. In addition, results from cognitive sciences can feed back into the visualization to make the visualization more user-friendly. For example, more intuitive input devices, such as cyber gloves which track the position of a users fingers, could be used to intuitively make selections or view modifications. The Appenzeller Visualization Laboratory is in a perfect position to enable research in all of these areas mentioned above. Sophisticated display systems are available which provide full immersion, ranging from single screens and head-mounted displays to full-size CAVE-type displays. This presentation will illustrate some examples for visualizations of data from the cognitive science realm and showcase display systems and some of their use cases
    corecore