1,720,963 research outputs found
Going 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
On the cohomology of moduli spaces of mixed characteristic shtukas
Get PDFWe study the cohomology of certain recently developed moduli spaces of mixed characteristic shtukas, which act as representation spaces for certain Lie groups and Galois groups. These spaces generalize Rapoport-Zink spaces, which provided a natural framework for studying moduli spaces of p-divisible groups. To construct them, one inputs the datum of a Lie group, a particular cocharacter for a maximal torus inside that group, and suitable data for a "G-isocrystal." In particular, for a judicious choice of this datum for the group GL_n, one recovers the Lubin-Tate tower at infinite level, whose cohomology is used to realize the transfer functors predicted by the Local Langlands Correspondence, which connect certain representations of the Lie group to representations of a Galois group. In this new setting, we discuss how some conjectures on the cohomology of Rapoport-Zink spaces at infinite level can be generalized to the setting of shtukas. We are particularly interested in the situation where the datum used to construct the spaces includes a cocharacter which is not minuscule, as the corresponding shtuka spaces have no classical analogue in the setting of Rapoport-Zink. In particular, when the Lie group involved is GL_n, we demonstrate how the Kottwitz and Harris-Viehmann conjectures for Rapoport-Zink spaces constructed via minuscule cocharacters implies similar conjectures about the cohomology of moduli spaces of shtukas. Our techniques rely crucially on very recent progress on the "Geometrization of the Local Langlands Program." In particular, the cohomological computations required to relate the conjectures will involve an interpretation using geometric Hecke operators, and this work will outline an intimate connection to Fargues's conjectures on the existence of Hecke eigensheaves on the stack of vector bundles on the Fargues-Fontaine curve. Our main results include a careful verification of the existence of a Hecke eigensheaf on the stack of rank 2 vector bundles on the curve associated to a supercuspidal representation of GL_2(ℚ_p), with an argument that works more generally given the validity of the classical conjectures for GL_n. Arguments for such a connection with Hecke eigensheaves go back to Fargues's original outline of his Geometrization program, but at the time lacked a sufficiently developed theory of diamonds and v-stacks to give a fully rigorous verification and model for all objects involved
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
Modularity of elliptic curves defined over function fields
Get PDFWe provide explicit equations for moduli spaces of Drinfeld shtukas over the
projective line with Γ(N), Γ_1(N) and Γ_0(N) level structures, where N is an effective
divisor on P^1 . If the degree of N is big enough, these moduli spaces are relative
surfaces.
We study how the moduli space of shtukas over P^1 with Γ_0(N) level structure,
Sht^{2,tr}(Γ_0(N)), can be used to provide a notion of motivic modularity for elliptic
curves defined over function fields. Elliptic curves over function fields are known to
be modular in the sense of admitting a parametrization from a Drinfeld modular curve,
provided that they have split multiplicative reduction at one place. We conjecture a
different notion of modularity that should cover the curves excluded by the reduction
hypothesis.
We use our explicit equations for Sht^{2,tr}(Γ_0(N)) to verify our modularity conjecture
in the cases where N = 2(0) + (1) + (∞) and N = 3(0) + (∞)
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Effective Galois descent for motives: the K3 case
Get PDFA theorem of Grothendieck tells us that if the Galois action on the Tate module of an abelian variety factors through a smaller field, then the abelian variety, up to isogeny and finite extension of the base, is itself defined over the smaller field.
Inspired by this, we give a Galois descent datum for a motive H over a field by asking that the Galois action on an l-adic realisation factor through a smaller field.
We conjecture that this descent datum is effective, that is if a motive H satisfies the above criterion, then it must itself descend to the smaller field.
We prove this conjecture for K3 surfaces, under some hypotheses.
The proof is based on Madapusi-Pera's extension of the Kuga-Satake construction to arbitrary fields
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