1,721,007 research outputs found
EUCLIDEAN WILSON LOOP AND AXIAL GAUGE
No full textA critical analysis is given in order to set up a well-defined perturbative expansion for Yang-Mills Euclidean theories within the axial gauge choice, using Cauchy principal value prescription to handle the spurious singularities. It is shown that, following a mathematically meaningful and unambiguous procedure, the exponential behavior of the Euclidean Wilson loop does not occur at variance with the covariant and planar gauge choices. A comparison with previous similar approaches and results is worked out in order to clearly understand the reasons for the breakdown of gauge invariance in the present case. In particular we can conclude that the so far proposed alternative prescriptions, which have been claimed to restore gauge invariance, should be carefully reexamined, at least for the Euclidean formulation
The Temporal Gauge Within The Dirac Constrained Dynamics
No full textThe Temporal Gauge Within The Dirac Constrained Dynamic
The Gluon Selfenergy In The Planar Gauge With The Leibbrandt-mandelstam Prescription
No full textWe develop an explicit calculation of the divergent part of the gluon self-energy in the planar gauge with the Leibbrandt-Mandelstam prescription for the spurious poles; the Lee-Ward identity for the self-energy tensor is also checked
Local And Nonlocal Counterterms In Algebraic Noncovariant Gauges
No full textA simple general argument is given to show that the counterterms in the space-like planar gauge with the Cauchy principal value prescription for the spurious singularities are local. This result is used to obtain limitations on the number and on the kind of nonlocal counterterms occurring in the light-cone case with the Mandelstam-Leibbrandt prescription
Residual Gauge Freedom And Brst Conditions In A Hamiltonian Formulation Of Algebraic Noncovariant Gauges
No full textA series of delicate points occurring in the quantization of Yang-Mills theories in algebraic non-covariant gauges is discussed. In particular the relation between subsidiary conditions and the seeming breakdown of the Lorentz covariance, the role of the residual gauge freedom and the relevance of the BRST procedure are focussed in the framework of the hamiltonian formulation
Yang-Mills theories in algebraic noncovariant gauges: Canonical quantization and renormalization
No full textYang-Mills theories in algebraic noncovariant gauges: Canonical quantization and renormalizatio
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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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