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Uniform bounds for the number of rational points on varieties over global fields
Full text linkWe extend the work of Salberger; Walsh; Castryck, Cluckers, Dittmann and Nguyen; and Vermeulen to prove the uniform dimension growth conjecture of Heath-Brown and Serre for varieties of degree at least 4 over global fields. As an intermediate step, we generalize the bounds of Bombieri and Pila to curves over global fields and in doing so we improve the Bε factor by a log(B) factor.Fil: Paredes, Marcelo Exequiel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Sasyk, Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad de Buenos Aires; Argentin
Uniform bounds for the number of rational points on varieties over global fields
Full text linkWe extend the work of Salberger; Walsh; Castryck, Cluckers, Dittmann and Nguyen; and Vermeulen to prove the uniform dimension growth conjecture of Heath-Brown and Serre for varieties of degree at least 4 over global fields. As an intermediate step, we generalize the bounds of Bombieri and Pila to curves over global fields and in doing so we improve the Bε factor by a log(B) factor.Fil: Paredes, Marcelo Exequiel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Sasyk, Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad de Buenos Aires; Argentin
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
Distributed sets on global fields and exceptional sets in diophantine geometry
No full textEsta tesis concierne el estudio de la densidad de puntos racionales en variades algebraicas y conjuntos definibles en estructuras o-minimales. La estrategia consiste en probar que los puntos racionales de estos conjuntos est´an mal distribuidos en clases residuales para muchos módulos primos. Primero, probamos que un conjunto de puntos afines o proyectivos con coordenadas en un cuerpo global, de altura acotada que ocupa pocas clases residuales para muchos módulos primos debe estar esencialmente contenido en el conjunto de ceros de un polinomio de grado y coeficientes de altura peque˜nos. Esto generaliza resultados de Walsh. Luego, aplicamos para estudiar una conjetura de Wilkie acerca de la distribución de los puntos racionales en ciertas estructuras o-minimales, y probamos que esta conjetura es equivalente a que ciertos conjuntos de puntos racionales de altura acotada estén mal distribuidos a nivel de clases residuales para muchos primos.This thesis concerns the study of the density of rational points on algebraic varieties and definable sets in o-minimal structures. The strategy consist in showing that the rational points of these sets are badly distributed in residual classes for many prime moduli. First, we prove that a set of affine or projective points with coordinates lying in a global field, with bounded height, that occupies few residual classes for many prime moduli must be essentially contained in the zero locus of a polynomial of small degree and height. This generalizes results of Walsh. Then, we apply this result to study a conjecture of Wilkie about the distribution of rational points on certain o-minimal structures, and we prove that this conjecture is equivalent to the fact that certain sets of rational points of bounded height are badly distributed at the level of residual classes for many prime moduli.Fil: Paredes, Marcelo Exequiel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Distributed sets on global fields and exceptional sets in diophantine geometry
Full text linkEsta tesis concierne el estudio de la densidad de puntos racionales en variades algebraicas y conjuntos definibles en estructuras o-minimales. La estrategia consiste en probar que los puntos racionales de estos conjuntos est´an mal distribuidos en clases residuales para muchos módulos primos. Primero, probamos que un conjunto de puntos afines o proyectivos con coordenadas en un cuerpo global, de altura acotada que ocupa pocas clases residuales para muchos módulos primos debe estar esencialmente contenido en el conjunto de ceros de un polinomio de grado y coeficientes de altura peque˜nos. Esto generaliza resultados de Walsh. Luego, aplicamos para estudiar una conjetura de Wilkie acerca de la distribución de los puntos racionales en ciertas estructuras o-minimales, y probamos que esta conjetura es equivalente a que ciertos conjuntos de puntos racionales de altura acotada estén mal distribuidos a nivel de clases residuales para muchos primos.This thesis concerns the study of the density of rational points on algebraic varieties and definable sets in o-minimal structures. The strategy consist in showing that the rational points of these sets are badly distributed in residual classes for many prime moduli. First, we prove that a set of affine or projective points with coordinates lying in a global field, with bounded height, that occupies few residual classes for many prime moduli must be essentially contained in the zero locus of a polynomial of small degree and height. This generalizes results of Walsh. Then, we apply this result to study a conjecture of Wilkie about the distribution of rational points on certain o-minimal structures, and we prove that this conjecture is equivalent to the fact that certain sets of rational points of bounded height are badly distributed at the level of residual classes for many prime moduli.Fil: Paredes, Marcelo Exequiel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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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