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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

On the Unramified Fontaine-Mazur Conjecture and its generalizations

Luo, Yufan 08 December 2023 (has links)
Diese Dissertation untersucht Galois-Erweiterungen von Zahlkörpern und die Unverzweigte Fontaine-Mazur-Vermutung für p-adische Galois-Darstellungen und deren Verallgemeinerungen. Wir beweisen viele grundlegende Fälle der Vermutung und liefern einige nützliche Kriterien zur Überprüfung. Darüber hinaus schlagen wir mehrere verschiedene Strategien vor, um die Vermutung anzugreifen und auf einige spezielle Fälle zu reduzieren. Wir beweisen auch viele neue Ergebnisse der Vermutung im zweidimensionalen Fall. Als Anwendung beweisen wir die Endlichkeit der unverzweigten Galois-Deformationsringe unter der Annahme eines speziellen Falles der Vermutung und geben einige Gegenbeispiele zur sogenannten Dimension-Vermutung für Galois-Deformationsringe unter der Annahme der Vermutung. / This thesis studies Galois extensions of number fields, and the Unramified Fontaine-Mazur Conjecture for p-adic Galois representations and its generalizations. We prove many basic cases of the conjecture, and provide some useful criterions for verifying it. In addition, we propose several different strategies to attack the conjecture and reduce it to some special cases. We also prove many new results of the conjecture in the two-dimensional case. As an application, we prove the finiteness of unramified Galois deformation rings assuming a special case of the conjecture, and we give some counterexamples to the so-called dimension conjecture for Galois deformation rings assuming the conjecture.
12

Propriedades homologicas de grupos pro-p / Homological properties of pro-p groups

Martin, Maria Eugenia 04 August 2009 (has links)
Orientador: Dessislava Hristova Kochloukova / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-13T12:02:14Z (GMT). No. of bitstreams: 1 Martin_MariaEugenia_M.pdf: 974097 bytes, checksum: 862be4d1ac3b05cc1a28ba59cf6c0460 (MD5) Previous issue date: 2009 / Resumo: Nesta dissertação discutimos propriedades homológicas de grupos discretos e grupos pro-p. Em particular trabalhamos com grupos abstratos de dualidade de Poincaré orientáveis de dimensão três e seu completamento pro-p. Os primeiros capítulos da dissertação incluem uma exposição sobre as propriedades homológicas básicas de grupos abstratos e grupos pro-p. Finalmente, descrevemos um resultado recente de [KZ], publicado em Transactions MAS ( 2008), que clássica quando o completamento pro-p de um grupo de dualidade de Poincaré orientável de dimensão três de um grupo pro-p de dualidade de Poincaré orientável de dimensão três / Abstract: In this dissertation we discuss homological properties of discrete groups and pro-p groups. In particular we work with groups of abstract of Poincaré duality of dimension three steerable and its pro-p completion. The first chapters of the dissertation include a presentation on the basic homological properties of abstract groups and pro-p groups. Finally, we describe a recent result of [KZ], published in Transactions AMS (2008), which ranks as the pro-p completion of a group of Poincare-steerable dual dimension of three is a group of pro-p duality of Poincare -steerable in three dimensions / Mestrado / Mestre em Matemática
13

Propriedades aritmeticas de corpos com um anel de valorização compativel com o radical de Kaplansky / Arithimetical properties of fields with a valuation ring compatible with the Kaplansky's Radical

Dario, Ronie Peterson 25 March 2008 (has links)
Orientador: Antonio Jose Engler / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-10T18:05:59Z (GMT). No. of bitstreams: 1 Dario_RoniePeterson_D.pdf: 1951766 bytes, checksum: afa64043636e06c86924e24d6fe65f43 (MD5) Previous issue date: 2008 / Resumo: Esta tese é um estudo das propriedades aritméticas de corpos que possuem um anel de valorização compatível com o Radical de Kaplansky. São utilizados os métodos da teoria algébrica das formas quadráticas, teoria de Galois e principalmente, a teoria de valorizações em corpos. Apresentamos um novo método para a construção de corpos com Radical de Kaplansky não trivial. Demonstramos uma versão do Teorema 90 de Hilbert para o radical. Para uma álgebra quaterniônica D, demonstramos que um anel de valorização do centro de D possui extensão para um anel de valorização total e invariante de D se, e somente se, for compatível com o Radical de Kaplansky / Abstract: This thesis is a study of the arithmetical properties of fields with a valuation ring compatible with the Kaplansky¿s Radical. The methods utilized are algebraic theory of quadratic forms, Galois theory and valuation theory over fields. We present a new construction method of fields with non-trivial Kaplansky¿s Radical. We also prove a version of the Hilbert¿s 90 Theorem for the radical. Let D a quaternion algebra and F the center of D. A valuation ring of F has a extension to a total and invariant valuation ring of D iff is compatible with the Kaplansky¿s Radical / Doutorado / Algebra / Doutor em Matemática
14

Completamentos Pro-p de grupos de dualidade de Poincaré / Pro-p completions of Poincaré duality groups

Lima, Igor dos Santos, 1983- 08 March 2012 (has links)
Orientador: Dessislava Hristova Kochloukova / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-20T17:04:33Z (GMT). No. of bitstreams: 1 Lima_IgordosSantos_D.pdf: 1446540 bytes, checksum: 1e68bfb627d234fa97739cd2e813b4a9 (MD5) Previous issue date: 2012 / Resumo: Neste trabalho, nos Teoremas Principais, damos condições suficientes para que o completamento pro-p de um grupo abstrato PDn seja virtualmente um grupo pro-p PDs para algum s ? n - 2 com n ? 4. Esse resultado é uma generalização do Teorema 3 em [K-2009]. Nossa prova é baseada em [K-2009] e nos resultados de A. A. Korenev [Ko-2004] e [Ko-2005]. Além disso, damos alguns exemplos de grupos que satisfazem as condições dos Teoremas Principais / Abstract: In this work we give in the Main Theorems suffiient conditions for that the pro- p completion of an abstract orientable PDn group to be virtually a pro-p PDs group for some s ? n - 2 with n ? 4. This result is a generalization of the Theorem 3 in [K-2009]. Our proof is based on [K-2009] and on the results of A. A. Korenev [Ko-2004] and [Ko-2005]. Furthermore we give some examples of groups that satisfy the conditions of the Main Theorems / Doutorado / Matematica / Doutor em Matemática
15

On some Density Theorems in Number Theory and Group Theory

Bardestani, Mohammad 08 1900 (has links)
Gowers, dans son article sur les matrices quasi-aléatoires, étudie la question, posée par Babai et Sos, de l'existence d'une constante $c>0$ telle que tout groupe fini possède un sous-ensemble sans produit de taille supérieure ou égale a $c|G|$. En prouvant que, pour tout nombre premier $p$ assez grand, le groupe $PSL_2(\mathbb{F}_p)$ (d'ordre noté $n$) ne posséde aucun sous-ensemble sans produit de taille $c n^{8/9}$, il y répond par la négative. Nous allons considérer le probléme dans le cas des groupes compacts finis, et plus particuliérement des groupes profinis $SL_k(\mathbb{Z}_p)$ et $Sp_{2k}(\mathbb{Z}_p)$. La premiére partie de cette thése est dédiée à l'obtention de bornes inférieures et supérieures exponentielles pour la mesure suprémale des ensembles sans produit. La preuve nécessite d'établir préalablement une borne inférieure sur la dimension des représentations non-triviales des groupes finis $SL_k(\mathbb{Z}/(p^n\mathbb{Z}))$ et $Sp_{2k}(\mathbb{Z}/(p^n\mathbb{Z}))$. Notre théoréme prolonge le travail de Landazuri et Seitz, qui considérent le degré minimal des représentations pour les groupes de Chevalley sur les corps finis, tout en offrant une preuve plus simple que la leur. La seconde partie de la thése à trait à la théorie algébrique des nombres. Un polynome monogéne $f$ est un polynome unitaire irréductible à coefficients entiers qui endengre un corps de nombres monogéne. Pour un nombre premier $q$ donné, nous allons montrer, en utilisant le théoréme de densité de Tchebotariov, que la densité des nombres premiers $p$ tels que $t^q -p$ soit monogéne est supérieure ou égale à $(q-1)/q$. Nous allons également démontrer que, quand $q=3$, la densité des nombres premiers $p$ tels que $\mathbb{Q}(\sqrt[3]{p})$ soit non monogéne est supérieure ou égale à $1/9$. / Gowers in his paper on quasirandom groups studies a question of Babai and Sos asking whether there exists a constant $c > 0$ such that every finite group $G$ has a product-free subset of size at least $c|G|$. Answering the question negatively, he proves that for sufficiently large prime $p$, the group $\mathrm{PSL}_2(\mathbb{F}_p)$ has no product-free subset of size $\geq cn^{8/9}$, where $n$ is the order of $\mathrm{PSL}_2(\mathbb{F}_p)$. We will consider the problem for compact groups and in particular for the profinite groups $\SL_k(\mathh{Z}_p)$ and $\Sp_{2k}(\mathbb{Z}_p)$. In Part I of this thesis, we obtain lower and upper exponential bounds for the supremal measure of the product-free sets. The proof involves establishing a lower bound for the dimension of non-trivial representations of the finite groups $\SL_k(\mathbb{Z}/(p^n\mathbb{Z}))$ and $\Sp_{2k}(\mathbb{Z}/(p^n\mathbb{Z}))$. Indeed, our theorem extends and simplifies previous work of Landazuri and Seitz, where they consider the minimal degree of representations for Chevalley groups over a finite field. In Part II of this thesis, we move to algebraic number theory. A monogenic polynomial $f$ is a monic irreducible polynomial with integer coefficients which produces a monogenic number field. For a given prime $q$, using the Chebotarev density theorem, we will show the density of primes $p$, such that $t^q-p$ is monogenic, is greater than or equal to $(q-1)/q$. We will also prove that, when $q=3$, the density of primes $p$, which $\mathbb{Q}(\sqrt[3]{p})$ is non-monogenic, is at least $1/9$.
16

投射有限群表現之形變理論 / Deformation Theory of Representations of Profinite Groups

周惠雯, Chou, Hui Wen Unknown Date (has links)
在本碩士論文中, 我們闡述了投射有限群表現, 以及其形變理論。 我們亦特別研究這些表示在 GL_1 和 GL_2 之形變, 並且給了可表示化 的判定準則。 最後, 我們解釋相對應的泛形變環之扎里斯基切空間與 群餘調之關連, 並計算了 GL_1 的泛形變表現。 / In this master thesis, we give an exposition of the deformation theory of representations for GL_1 and GL_2, respectively, of certain profinite groups. We give rigidity conditions of the fixed representation and verify several conditions for the representability. Finally, we interpret the Zariski tangent spaces of respective universal deformation rings as certain group cohomology and calculate the universal deformation for GL_1.
17

On some Density Theorems in Number Theory and Group Theory

Bardestani, Mohammad 08 1900 (has links)
Gowers, dans son article sur les matrices quasi-aléatoires, étudie la question, posée par Babai et Sos, de l'existence d'une constante $c>0$ telle que tout groupe fini possède un sous-ensemble sans produit de taille supérieure ou égale a $c|G|$. En prouvant que, pour tout nombre premier $p$ assez grand, le groupe $PSL_2(\mathbb{F}_p)$ (d'ordre noté $n$) ne posséde aucun sous-ensemble sans produit de taille $c n^{8/9}$, il y répond par la négative. Nous allons considérer le probléme dans le cas des groupes compacts finis, et plus particuliérement des groupes profinis $SL_k(\mathbb{Z}_p)$ et $Sp_{2k}(\mathbb{Z}_p)$. La premiére partie de cette thése est dédiée à l'obtention de bornes inférieures et supérieures exponentielles pour la mesure suprémale des ensembles sans produit. La preuve nécessite d'établir préalablement une borne inférieure sur la dimension des représentations non-triviales des groupes finis $SL_k(\mathbb{Z}/(p^n\mathbb{Z}))$ et $Sp_{2k}(\mathbb{Z}/(p^n\mathbb{Z}))$. Notre théoréme prolonge le travail de Landazuri et Seitz, qui considérent le degré minimal des représentations pour les groupes de Chevalley sur les corps finis, tout en offrant une preuve plus simple que la leur. La seconde partie de la thése à trait à la théorie algébrique des nombres. Un polynome monogéne $f$ est un polynome unitaire irréductible à coefficients entiers qui endengre un corps de nombres monogéne. Pour un nombre premier $q$ donné, nous allons montrer, en utilisant le théoréme de densité de Tchebotariov, que la densité des nombres premiers $p$ tels que $t^q -p$ soit monogéne est supérieure ou égale à $(q-1)/q$. Nous allons également démontrer que, quand $q=3$, la densité des nombres premiers $p$ tels que $\mathbb{Q}(\sqrt[3]{p})$ soit non monogéne est supérieure ou égale à $1/9$. / Gowers in his paper on quasirandom groups studies a question of Babai and Sos asking whether there exists a constant $c > 0$ such that every finite group $G$ has a product-free subset of size at least $c|G|$. Answering the question negatively, he proves that for sufficiently large prime $p$, the group $\mathrm{PSL}_2(\mathbb{F}_p)$ has no product-free subset of size $\geq cn^{8/9}$, where $n$ is the order of $\mathrm{PSL}_2(\mathbb{F}_p)$. We will consider the problem for compact groups and in particular for the profinite groups $\SL_k(\mathh{Z}_p)$ and $\Sp_{2k}(\mathbb{Z}_p)$. In Part I of this thesis, we obtain lower and upper exponential bounds for the supremal measure of the product-free sets. The proof involves establishing a lower bound for the dimension of non-trivial representations of the finite groups $\SL_k(\mathbb{Z}/(p^n\mathbb{Z}))$ and $\Sp_{2k}(\mathbb{Z}/(p^n\mathbb{Z}))$. Indeed, our theorem extends and simplifies previous work of Landazuri and Seitz, where they consider the minimal degree of representations for Chevalley groups over a finite field. In Part II of this thesis, we move to algebraic number theory. A monogenic polynomial $f$ is a monic irreducible polynomial with integer coefficients which produces a monogenic number field. For a given prime $q$, using the Chebotarev density theorem, we will show the density of primes $p$, such that $t^q-p$ is monogenic, is greater than or equal to $(q-1)/q$. We will also prove that, when $q=3$, the density of primes $p$, which $\mathbb{Q}(\sqrt[3]{p})$ is non-monogenic, is at least $1/9$.
18

Encoding and detecting properties in finitely presented groups

Gardam, Giles January 2017 (has links)
In this thesis we study several properties of finitely presented groups, through the unifying paradigm of encoding sought-after group properties into presentations and detecting group properties from presentations, in the context of Geometric Group Theory. A group law is said to be detectable in power subgroups if, for all coprime m and n, a group G satisfies the law if and only if the power subgroups G(<sup>m</sup>) and G(<sup>n</sup>) both satisfy the law. We prove that for all positive integers c, nilpotency of class at most c is detectable in power subgroups, as is the k-Engel law for k at most 4. In contrast, detectability in power subgroups fails for solvability of given derived length: we construct a finite group W such that W(<sup>2</sup>) and W(<sup>3</sup>) are metabelian but W has derived length 3. We analyse the complexity of the detectability of commutativity in power subgroups, in terms of finite presentations that encode a proof of the result. We construct a census of two-generator one-relator groups of relator length at most 9, with complete determination of isomorphism type, and verify a conjecture regarding conditions under which such groups are automatic. Furthermore, we introduce a family of one-relator groups and classify which of them act properly cocompactly on complete CAT(0) spaces; the non-CAT(0) examples are counterexamples to a variation on the aforementioned conjecture. For a subclass, we establish automaticity, which is needed for the census. The deficiency of a group is the maximum over all presentations for that group of the number of generators minus the number of relators. Every finite group has non-positive deficiency. For every prime p we construct finite p-groups of arbitrary negative deficiency, and thereby complete Kotschick's proposed classification of the integers which are deficiencies of Kähler groups. We explore variations and embellishments of our basic construction, which require subtle Schur multiplier computations, and we investigate the conditions on inputs to the construction that are necessary for success. A well-known question asks whether any two non-isometric finite volume hyperbolic 3-manifolds are distinguished from each other by the finite quotients of their fundamental groups. At present, this has been proved only when one of the manifolds is a once-punctured torus bundle over the circle. We give substantial computational evidence in support of a positive answer, by showing that no two manifolds in the SnapPea census of 72 942 finite volume hyperbolic 3-manifolds have the same finite quotients. We determine examples of sizeable graphs, as required to construct finitely presented non-hyperbolic subgroups of hyperbolic groups, which have the fewest vertices possible modulo mild topological assumptions.
19

Sobre Centralizadores de Automorfismos Coprimos em Grupos Profinitos e Álgebras de Lie / About Centralized coprime automorphisms Profinitos Groups and Lie Algebras

LIMA, Márcio Dias de 27 June 2011 (has links)
Made available in DSpace on 2014-07-29T16:02:19Z (GMT). No. of bitstreams: 1 Dissertacao Marcio Lima.pdf: 1529346 bytes, checksum: c6a80a13d55b40203c44877c4cdeb1f4 (MD5) Previous issue date: 2011-06-27 / A be an elementary abelian group of order q2, where q a prime number. In this paper we will study the influence of centering on the structure of automorphism groups profinitos in this sense if A acting as a coprime group of automorphisms on a group profinito G and CG(a) is periodic for each a 2 A#, then we will show that G is locally finite. It will be demonstrated also the case where A acts as a group of automorphisms of a group pro-p of G / Sejam A um grupo abeliano elementar de ordem q2, onde q um número primo. Neste trabalho estudamos a influência dos centralizadores de automorfismos na estrutura dos grupos profinitos, neste sentido se A age como um grupo de automorfismos coprimos sobre um grupo profinito G e que CG(a) é periódico para cada a 2 A#, então mostraremos que G é localmente finito. Será demonstrado também o caso onde A age como um grupo de automorfismos sobre um grupo pro-p de G.
20

Quantifiers and duality / Quantificateurs et dualité

Reggio, Luca 10 September 2018 (has links)
Le thème central de la présente thèse est le contenu sémantique des quantificateurs logiques. Dans leur forme la plus simple, les quantificateurs permettent d’établir l’existence, ou la non-existence, d’individus répondant à une propriété. En tant que tels, ils incarnent la richesse et la complexité de la logique du premier ordre, par delà la logique propositionnelle. Nous contribuons à l’analyse sémantique des quantificateurs, du point de vue de la théorie de la dualité, dans trois domaines différents des mathématiques et de l’informatique théorique. D’une part, dans la théorie des langages formels à travers la logique sur les mots. D’autre part, dans la logique intuitionniste propositionnelle et dans l’étude de l’interpolation uniforme. Enfin, dans la topologie catégorique et dans la sémantique catégorique de la logique du premier ordre. / The unifying theme of the thesis is the semantic meaning of logical quantifiers. In their basic form quantifiers allow to state theexistence, or non-existence, of individuals satisfying a property. As such, they encode the richness and the complexity of predicate logic, as opposed to propositional logic. We contribute to the semantic understanding of quantifiers, from the viewpoint of duality theory, in three different areas of mathematics and theoretical computer science. First, in formal language theory through the syntactic approach provided by logic on words. Second, in intuitionistic propositional logic and in the study of uniform interpolation. Third, in categorical topology and categorical semantics for predicate logic.

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