1,720,964 research outputs found
REDUCED HAMILTONIAN FOR INTERSECTING SHELLS
No full textThe gauge usually adopted for extracting the reduced Hamiltonian of a thin spherical shell of matter in general relativity, becomes singular when dealing with two or more intersecting shells.
We introduce here a more general class of gauges which is apt for dealing with intersecting shells.
As an application we give the hamiltonian treatment of two intersecting shells, both massive and massless.
Such a formulation is applied to the computation of the semiclassical tunneling probability of two shells.
The probability for the emission of two shells is simply the product of the separate probabilities thus showing no correlation in the emission probabilities in this model
Anomalous dimension with wrapping at four loops in N=4 SYM
No full textIn this paper we give all the details of the calculation that we presented in our previous paper arXiv:0712.3522, concerning the four-loop anomalous dimension of the Konishi descendant tr(\phi Z\phi Z-\phi \phi Z Z) in the SU(2) sector of the N=4 planar SYM theory. We explicitly consider all the wrapping diagrams that we compute using an N=1 superspace approach and Gegenbauer polynomial x-space techniques
Wrapping interactions and integrability in standard and beta-deformed N = 4 Super Yang-Mills
No full textFinite-size effects in the superconformal beta-deformed N=4 SYM
No full textWe study finite size effects for composite operators in the SU(2) sector of the superconformal beta-deformed N=4 SYM theory. In particular we concentrate on the spectrum of one single magnon. Since in this theory one-impurity states are non BPS we compute their anomalous dimensions including wrapping contributions up to four loops and discuss higher order effects
Wrapping at four loops in N=4 SYM
No full textAbstractWe present the planar four-loop anomalous dimension of the composite operator tr(ϕ[Z,ϕ]Z) in the flavour SU(2) sector of the N=4 SYM theory. At this loop order wrapping interactions are present: they give rise to contributions proportional to ζ(5) increasing the level of transcendentality of the anomalous dimension. In a sequel of this Letter all the details of our calculation will be reported
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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