1,720,975 research outputs found
Discretization effects and gauge independence for the electric and magnetic screening masses
No full textCucchieri A, Karsch F. Discretization effects and gauge independence for the electric and magnetic screening masses. In: Nuclear Physics B - Proceedings Supplements. Nuclear Physics B, Proceedings Supplments. Vol 83-84. ELSEVIER SCIENCE BV; 2000: 357-359.We evaluate the electric and magnetic screening masses from the long-distance behavior of the (temporal and spatial) gluon correlation functions, for pure SU(2) gauge theory at finite temperature. In order to investigate the gauge dependence of the screening masses we consider seven different gauges. We also evaluate these masses using different definitions of the lattice gluon field, corresponding to discretization errors of different orders
Continuum limits and exact finite-size-scaling functions for one-dimensional O(N)-invariant spin models
No full textPropagators and dimensional reduction of hot SU(2) gauge theory
No full textCucchieri A, Karsch F, Petreczky P. Propagators and dimensional reduction of hot SU(2) gauge theory. PHYSICAL REVIEW D. 2001;64(3): 036001.We investigate the large distance behavior of the electric and magnetic propagators of hot SU(2) gauge theory in different gauges using lattice simulations of the full four-dimensional (4D) theory and the effective, dimensionally reduced, 3D theory. A comparison of the 3D and 4D propagators suggests that dimensional reduction works surprisingly well down to the temperature T=2T(c). Within statistical uncertainty the electric screening mass is found to be gauge independent. The magnetic propagator, on the other hand, exhibits a complicated gauge dependent structure at low momentum
Screening in hot SU(2) gauge theory and propagators in 3d adjoint Higgs model
No full textCucchieri A, Karsch F, Petreczky P. Screening in hot SU(2) gauge theory and propagators in 3d adjoint Higgs model. In: Nuclear Physics B - Proceedings Supplements. NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS. Vol 94. ELSEVIER SCIENCE BV; 2001: 385-388.We investigate the large distance behavior of the electric and magnetic propagators of hot SU(2) gauge theory in different gauges using lattice simulations of the full 4d theory and the effective, dimensionally reduced 3d theory. A comparison of the 3d and 4d data for the propagators suggests that dimensional reduction works surprisingly well down to temperatures T similar to 2T(c). A detailed study of the volume dependence of magnetic propagators is performed. The electric propagators show exponential decay at large distances in all gauges considered and a possible gauge dependence of the electric screening mass turns out to be statistically insignificant
Application of the O(N)-hyperspherical harmonics to the study of the continuum limits of one-dimensional sigma-models and to the generation of high-temperature expansions in higher dimensions
No full textIn this talk we present the exact solution of the most general one-dimensional O(N)-invariant spin model taking values in the sphere S-N-1, with nearest-neighbour interactions, and we discuss the possible continuum limits. All these results are obtained using a high-temperature expansion in terms of hyperspherical harmonics. Applications in higher dimensions of the same technique are then discussed
Application of the O(N) hyperspherical harmonics to the study of the continuum limits of 1-d sigma models and to the generation of high-T expansions in higher dimensions
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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