15,455 research outputs found

    Finite-size scaling for the left-current correlator with non-degenerate quark masses

    Get PDF
    We study the volume dependence of the left-current correlator with non-degenerate quark masses to next-to-leading order in the chiral expansion. We consider three possible regimes: all quark masses are in the ϵ\epsilon-regime, all are in the pp-regime and a mixed-regime where the lighest quark masses satisfy mvΣV1m_v \Sigma V \leq 1 while the heavier msΣV1m_s \Sigma V \gg 1. These results can be used to match lattice QCD and the Chiral Effective Theory in a large but finite box in which the Compton wavelength of the lightest pions is of the order of the box size. We consider both the full and partially-quenched results.Comment: 27 pages, 4 figure

    Bendito Amor: Religion and Relationships among Married and Unmarried Latinos in Urban America

    Get PDF
    The family arrangements of Latinos in the U.S. are increasingly diverse, with growing numbers of Latino children living in households headed by married and unmarried parents. Latinos also tend to be more religious than the population at large. Yet no research has examined the associations between religion and relationship quality among married and unmarried Latinos. Using data from the Fragile Families and Child Wellbeing Study, which focuses on new parents in urban America, we find that the religious attendance of Latino fathers promotes higher-quality relationships among both fathers and mothers; by contrast, the effect of maternal attendance on relationship quality is insignificant or negative.

    Predictive Entropy Search for Efficient Global Optimization of Black-box Functions

    Full text link
    We propose a novel information-theoretic approach for Bayesian optimization called Predictive Entropy Search (PES). At each iteration, PES selects the next evaluation point that maximizes the expected information gained with respect to the global maximum. PES codifies this intractable acquisition function in terms of the expected reduction in the differential entropy of the predictive distribution. This reformulation allows PES to obtain approximations that are both more accurate and efficient than other alternatives such as Entropy Search (ES). Furthermore, PES can easily perform a fully Bayesian treatment of the model hyperparameters while ES cannot. We evaluate PES in both synthetic and real-world applications, including optimization problems in machine learning, finance, biotechnology, and robotics. We show that the increased accuracy of PES leads to significant gains in optimization performance

    Birth, death and diffusion of interacting particles

    Get PDF
    Individual-based models of chemical or biological dynamics usually consider individual entities diffusing in space and performing a birth-death type dynamics. In this work we study the properties of a model in this class where the birth dynamics is mediated by the local, within a given distance, density of particles. Groups of individuals are formed in the system and in this paper we concentrate on the study of the properties of these clusters (lifetime, size, and collective diffusion). In particular, in the limit of the interaction distance approaching the system size, a unique cluster appears which helps to understand and characterize the clustering dynamics of the model.Comment: 15 pages, 6 figures, Iop style. To appear in Journal of Physics A: Condensed matte

    A source of a quasi--spherical space--time: The case for the M--Q solution

    Full text link
    We present a physically reasonable source for an static, axially--symmetric solution to the Einstein equations. Arguments are provided, supporting our belief that the exterior space--time produced by such source, describing a quadrupole correction to the Schwarzschild metric, is particularly suitable (among known solutions of the Weyl family) for discussing the properties of quasi--spherical gravitational fields.Comment: 34 pages, 9 figures. To appear in GR

    Lower Bounds on the Redundancy of Huffman Codes with Known and Unknown Probabilities

    Full text link
    In this paper we provide a method to obtain tight lower bounds on the minimum redundancy achievable by a Huffman code when the probability distribution underlying an alphabet is only partially known. In particular, we address the case where the occurrence probabilities are unknown for some of the symbols in an alphabet. Bounds can be obtained for alphabets of a given size, for alphabets of up to a given size, and for alphabets of arbitrary size. The method operates on a Computer Algebra System, yielding closed-form numbers for all results. Finally, we show the potential of the proposed method to shed some light on the structure of the minimum redundancy achievable by the Huffman code

    Graded infinite order jet manifolds

    Full text link
    The relevant material on differential calculus on graded infinite order jet manifolds and its cohomology is summarized. This mathematics provides the adequate formulation of Lagrangian theories of even and odd variables on smooth manifolds in terms of the Grassmann-graded variational bicomplex.Comment: 30 page
    corecore