1,720,974 research outputs found
Degree theory for C1-Fredholm mappings of index 0
No full textWe develop a degree theory for C 1 Fredholm mappings of index 0 between Banach spaces and Banach manifolds. As in earlier work devoted to the C 2 case, our approach is based upon the concept of parity of a curve of linear Fredholm operators of index 0. This avoids considerations about Fredholm structures involved in other approaches and leads to a theory as complete as that of Leray-Schauder in a much broader setting. In particular, the well-known possible sign change under homotopy is fully elucidated. The technical difficulty arising with C a versus C 2 Fredholm mappings of index 0 is notorious: with only C 1 smoothness, the Sarff-Smale theorem is no longer available to handle crucial issues involving homotopy. In this work, this difficulty is overcome by using a new approximation theorem for C a Fredholm mappings of arbitrary index instead of the Sard-Smale theorem when dealing with homotopie
Orientability of Fredholm families and topological degree
Get PDFWe construct a degree theory for oriented Fredholm mappings of index zero between open subsets of Banach spaces and between Banach manifolds. Our approach is based on the orientation of Fredholm mappings: it does not use Fredholm structures on the domain and target spaces. We provide a computable formula for the change in degree through an admissible homotopy that is necessary for applications to global bifurcation. The notion of orientation enables us to establish rather precise relationships between our degree and many other degree theories for particular classes of Fredholm maps, including the Elworthy-Tromba degree, which have appeared in the literature in a seemingly unrelated manner
Topological degree for nonlinear Fredholm operators
No full textWe introduce an integer-valued topological degree for proper C2-Fredholm mappings. The changes of the degree under homotopy are described by the parity. We use the degree to prove a global bifurcation theore
Degree theory for proper C^2-Fredholm maps I
No full textWe construct a new integer valued degree theory for proper C2 Fredholm maps of index 0, defined on a simply connected domain. The degree depends on the choice of a point in the domain called "base point". However the change of the base point at most can change the sign of the degree. Also the degree is invariant by homotopy only up to a sig. However the change in degree in both cases is computable using a homotopy invariant of paths of Fredholm operators called parity. We use this in order to extend the Krasnoselskii-Rabinowitz global bifurcation theorem to Fredholm map
Degree Theory for proper C2-Fredholm maps. Covariant theory.
No full textCongruences for the topological degree of a proper Fredholm map of index 0, covariant under the action of a Lie group are obtained
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
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
- …
