1,721,553 research outputs found
Small coupling limit and multiple solutions to the Dirichlet Problem for Yang-Mills connections in 4 dimensions - Part III
No full textIn this paper, the third of this series, we prove that the spaces A,p
k (A0; q) and B,p
0,k(A0; q)
which contain Lp
k-approximate solutions to the Dirichlet problem for the -Yang Mills equations
on a four dimensional disk B4, carry a natural manifold structure (more precisely a
natural structure of Banach bundle), for p(k+1) > 4. All results apply also if B4 is replaced
by a general compact manifold with boundary, and SU(2) is replaced by any compact Lie
group. We also construct bases for the tangent space to the space of approximate solutions,
thus showing that this space is 8-dimensional for sufficiently small, and prove some technical
results used in Parts I and II for the proof of the existence of multiple solution and, in
particular, non-minimal ones, for this non-compact variational problem
Small coupling limit and multiple solutions to the Dirichlet problem for Yang-Mills connections in four dimensions. II
No full textIn this paper (Part I) and its sequels (Part II and Part III), we analyze the structure
of the space of solutions to the -Dirichlet problem for the Yang-Mills equations on the
4-dimensional disk, for small values of the coupling constant . These are in one-to-one correspondence
with solutions to the Dirichlet problem for the Yang Mills equations, for small
boundary data A0. We prove the existence of multiple solutions, and, in particular, non minimal
ones, and establish a Morse Theory for this non-compact variational problem. In part
I, we describe the problem, state the main theorems and do the first part of the proof. This
consists in transforming the problem into a finite dimensional problem, by seeking solutions
that are approximated by the connected sum of a minimal solution with an instanton, plus a
correction term due to the boundary. An auxiliary equation is introduced that allows us to
solve the problem orthogonally to the tangent space to the space of approximate solutions.
In Part II, the finite dimensional problem is solved via the Ljusternik-Schirelman theory, and
the existence proofs are completed. In Part III, we prove that the space of gauge equivalence
classes of Sobolev connections with prescribed boundary value is a smooth manifold, as well
as some technical lemmas essential to the proofs of Part I. The methods employed still work
when B4 is replaced by a general compact manifold with boundary, and SU(2) is replaced
by any compact Lie group
Purification and characterization of a novel 70-kDa brain protein associated with seizure activities.
No full text
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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