Dissertations / Theses: 'Galois ring'

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Hedenlund, Alice. "Galois Theory of Commutative Ring Spectra." Thesis, KTH, Matematik (Avd.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-183512.

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This thesis discusses Galois theory of ring spectra in the sense of John Rognes. The aim is to give a clear introduction that provides a solid foundation for further studies into the subject. We introduce ring spectra using the symmetric spectra of Hovey, Shipley and Smith, and discuss the symmetric monoidal model structure on this category. We deﬁne and give results for Galois extensions of these objects. We also give examples involving Eilenberg-Mac Lane spectra of commutative rings, topological K-theory spectra and cochain algebras of these. Galois extensions of ring spectra are compared to Ga-lois extensions of commutative rings especially relating to faithfulness, a property that is implicit in the latter, but not in the former. This is proven by looking at extensions of cochain algebras using Eilenberg-Mac Lane spectra. We end by contrasting this to cochain algebra extensions using K-theory spectra, and show that such extensions are not Galois, using methods of Baker and Richter.
Denna uppsats behandlar Galoisutvidgningar av ringspektra som först introducerade av Rognes. Målet är att ge en klar introduktion för en sta-bil grund för vidare studier inom ämnet. Vi introducerar ringspektra genom att använda oss av symmetris-ka spektra utvecklade av Hovey, Shipley och Smith, och diskuterar den symmetriskt monoidiala modelstrukturen på denna kategori. Vi deﬁnierar och ger resultat för Galoisutvidgningar av dessa objekt. Vi ger också en mängd exempel, som till exempel utvidgningar av Eilenberg-Mac Lane spektra av kommutativa ringar, topologiska K-teorispektra och koked-jealgebror. Galoisutvidgningar av ringspektra jämförs med Galoisutvidgningar av kommutativa ringar, speciellt med avseende pa˚ trogenhet, en egenskap som ¨ar en inneboende egenskap hos den senare men inte i den förra. Detta visas genom att betrakta utvidgningar av kokedjealgebror av Eilenberg-Mac Lane spektra. Vi avslutar med att jämföra detta med kokedjealgebrautvidgningar av K-teorispektra och visar att sådana inte är Galois genom att använda metoder utvecklade av Baker och Richter

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Abrahamsson, Björn. "Architectures for Multiplication in Galois Rings." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2396.

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This thesis investigates architectures for multiplying elements in Galois rings of the size 4^m, where m is an integer.

The main question is whether known architectures for multiplying in Galois fields can be used for Galois rings also, with small modifications, and the answer to that question is that they can.

Different representations for elements in Galois rings are also explored, and the performance of multipliers for the different representations is investigated.

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Armand, Marc Andre. "Contributions to the decoding of linear codes over a Galois ring." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297851.

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Moon, Yong Suk. "Galois Deformation Ring and Barsotti-Tate Representations in the Relative Case." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493581.

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In this thesis, we study finite locally free group schemes, Galois deformation rings, and Barsotti-Tate representations in the relative case. We show three independent but related results, assuming p > 2. First, we give a simpler alternative proof of Breuil’s result on classifying finite flat group schemes over the ring of integers of a p-adic field by certain Breuil modules [5]. Second, we prove that the locus of potentially semi-stable representations of the absolute Galois group of a p-adic field K with a specified Hodge-Tate type and Galois type cuts out a closed subspace of the generic fiber of a given Galois deformation ring, without assuming that K/Qp is finite. This is an extension of the corresponding result of Kisin when K/Qp is finite [19]. Third, we study the locus of Barsotti-Tate representations in the relative case, via analyzing certain extendability of p-divisible groups. We prove that when the ramification index is less than p-1, the locus of relative Barsotti-Tate representations cuts out a closed subspace of the generic fiber of a Galois deformation ring, if the base scheme is 2-dimensional satisfying some conditions. When the ramification index is greater than p-1, we show that such a result does not hold in general.
Mathematics

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5

Szabo, Steve. "Convolutional Codes with Additional Structure and Block Codes over Galois Rings." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1257792383.

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Pinnawala, Nimalsiri, and nimalsiri pinnawala@rmit edu au. "Properties of Trace Maps and their Applications to Coding Theory." RMIT University. Mathematical and Geospatial Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080515.121603.

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In this thesis we study the application of trace maps over Galois fields and Galois rings in the construction of non-binary linear and non-linear codes and mutually unbiased bases. Properties of the trace map over the Galois fields and Galois rings has been used very successfully in the construction of cocyclic Hadamard, complex Hadamard and Butson Hadamard matrices and consequently to construct linear codes over integers modulo prime and prime powers. These results provide motivation to extend this work to construct codes over integers modulo . The prime factorization of integers paved the way to focus our attention on the direct product of Galois rings and Galois fields of the same degree. We define a new map over the direct product of Galois rings and Galois fields by using the usual trace maps. We study the fundamental properties of the this map and notice that these are very similar to that of the trace map over Galois rings and Galois fields. As such this map called the trace-like map and is used to construct cocyclic Butson Hadamard matrices and consequently to construct linear codes over integers modulo . We notice that the codes construct in this way over the integers modulo 6 is simplex code of type . A further generalization of the trace-like map called the weighted-trace map is defined over the direct product of Galois rings and Galois fields of different degrees. We use the weighted-trace map to construct some non-linear codes and mutually unbiased bases of odd integer dimensions. Further more we study the distribution of over the Galois fields of degree 2 and use it to construct 2-dimensional, two-weight, self-orthogonal codes and constant weight codes over integers modulo prime.

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Herschend, Martin. "On the Clebsch-Gordan problem for quiver representations." Doctoral thesis, Uppsala University, Department of Mathematics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8663.

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On the category of representations of a given quiver we define a tensor product point-wise and arrow-wise. The corresponding Clebsch-Gordan problem of how the tensor product of indecomposable representations decomposes into a direct sum of indecomposable representations is the topic of this thesis.

The choice of tensor product is motivated by an investigation of possible ways to modify the classical tensor product from group representation theory to the case of quiver representations. It turns out that all of them yield tensor products which essentially are the same as the point-wise tensor product.

We solve the Clebsch-Gordan problem for all Dynkin quivers of type A, D and E₆, and provide explicit descriptions of their respective representation rings. Furthermore, we investigate how the tensor product interacts with Galois coverings. The results obtained are used to solve the Clebsch-Gordan problem for all extended Dynkin quivers of type Ã_n and the double loop quiver with relations βα=αβ=αⁿ=βⁿ=0.

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Lodh, Rémi Shankar. "Galois cohomology of Fontaine rings." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=984696563.

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Turner, Ryan. "The Galois theory of matrix C-rings." Thesis, Swansea University, 2006. https://cronfa.swan.ac.uk/Record/cronfa42607.

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Blackford, J. Thomas. "Permutation groups of extended cyclic codes over Galois Rings /." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488186329502909.

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Raji, Mehrdad Ahmadzadeh. "High power residue codes over Galois rings and related lattices." Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248091.

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Villafranca, Rogério. "Decodificação de códigos sobre anéis de Galois." reponame:Repositório Institucional da UFABC, 2014.

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Orientador: Prof. Dr. Francisco César Polcino Milies
Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Matemática , 2014.
Códigos sobre anéis vem sendo estudados desde a década de 70 e hoje sabe-se que alguns códigos não-lineares sobre corpos são imagens de códigos lineares sobre anéis Zpm. Neste trabalho, lidamos com códigos sobre Anéis de Galois, que são uma generalização tanto para corpos finitos quanto para anéis Zpm. Em uma primeira parte dedicada a anéis, definimos anéis de Galois como um caso particular de anéis locais, mostramos a equivalência entre essa definição e a construção clássica desses anéis como extensões de Zpm e apresentamos propriedades importantes. Em seguida, na parte referente à Teoria de Códigos, descrevemos as bases necessárias desse assunto e apresentamos um método permitindo a obtenção de um algoritmo de decodificação para um código sobre um anel de Galois a partir de algoritmos de decodificação para códigos lineares sobre o corpo de resíduos desse anel.
Codes over rings are a research subject since the 70¿s and today is well known that some non-linear codes over fields are images of linear codes over Zpm rings. In this work we deal with codes over Galois rings, which generalize both finite fields and Zpm rings. In a first part concerning ring theory, we define Galois rings as a particular case of local rings, show the equivalence of this definition to the classical construction of such rings as extensions of Zpm and present important properties of these structures. Next, concerning Coding Theory, we describe the basic facts of this subject and present a method that alows us to obtain decoding alogrithms for a linear code over a Galois ring from decoding algorithms for linear codes over the residue field of that ring.

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Katz, Daniel J. Wilson R. M. "On p-adic estimates of weights in Abelian codes over Galois rings /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-05312005-175744.

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14

Guiraud, David-Alexandre [Verfasser], and Gebhard [Akademischer Betreuer] Böckle. "A framework for unobstructedness of Galois deformation rings / David-Alexandre Guiraud ; Betreuer: Gebhard Böckle." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180610385/34.

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Rzedowski-Calderon, Martha. "Galois module structure of rings of integers and automorphism groups of congruence function fields /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu148759571215722.

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Park, Chol. "Semi-Stable Deformation Rings in Hodge-Tate Weights (0,1,2)." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293444.

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In this dissertation, we study semi-stable representations of G(Q(p)) and their mod p-reductions, which is a part of the problem in which we construct deformation spaces whose characteristic 0 closed points are the semi-stable lifts with Hodge-Tate weights (0, 1, 2) of a fixed absolutely irreducible residual representation ρ : G(Q(p)) → GL₃(F(p)). We first classify the isomorphism classes of semi-stable representations of G(Q(p)) with regular Hodge-Tate weights, by classifying admissible filtered (phi,N)-modules with Hodge-Tate weights (0, r, s) for 0 < r < s. We also construct a Galois stable lattice in some irreducible semi-stable representations with Hodge-Tate weights (0, 1, 2), by constructing strongly divisible modules, which is an analogue of Galois stable lattices on the filtered (ɸ, N)-module side. We compute the reductions mod p of the corresponding Galois representations to the strongly divisible modules we have constructed, by computing Breuil modules, which is, roughly speaking, mod p-reduction of strongly divisible modules. We also determine which Breuil modules corresponds to irreducible mod p representations of G(Q(p)).

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Khalil, Maya. "Classes de Steinitz, codes cycliques de Hamming et classes galoisiennes réalisables d'extensions non abéliennes de degré p³." Thesis, Valenciennes, 2016. http://www.theses.fr/2016VALE0012/document.

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Sampaio, Ingrid Araujo. "Codigos ciclicos sobre aneis locais e suas relações com a transformada discreta de Fourier." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259782.

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Orientador: Reginaldo Palazzo Junior
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Neste trabalho apresentamos algumas relações existentes entre codigos c'clicos e a transformada discreta de Fourier ambos sobre aneis locais. Para isso, 'e necessario a identificação do grupo das unidades associado a cada um dos anéis considerados. Como consequencia, codigos ciclicos sobre tais aneis podem ser construidos. Em seguida, construimos geradores de sequencias atravees dos registros de deslocamento com realimentação linear (LFSR), a partir dos polinomios geradores, cujos coeficientes pertencem a um corpo finito e a um anel comutativo finito local com identidade. Finalmente, realizamos a transformada discreta de Fourier por meio do polinomio gerador dos codigos ciclicos sobre aneis locais
Abstract: In this research we present some existing relationships between cyclic codes and discrete Fourier transform both local rings. For this, it is necessary to identify the groups of unit associated with each corresponding local ring. As a consequence, cyclic codes over these rings may be constructed. Next, we construct sequence generators by use of linear feedback shift register (LFSR), from generator polynomials whose coefficients belong either to finite field or to a local finite commutative ring with identity. Finally, the discrete Fourier transform is realized by use of the generator polynomial of cyclic codes over local rings
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica

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Dario, Ronie Peterson. "Propriedades aritmeticas de corpos com um anel de valorização compativel com o radical de Kaplansky." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306508.

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Orientador: Antonio Jose Engler
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
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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

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Ferreira, Mauricio de Araujo 1982. "Algebras biquaternionicas : construção, classificação e condições de existencia via formas quadraticas e involuções." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306541.

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Orientador: Antonio Jose Engler
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
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Resumo: Neste trabalho, estudamos as álgebras biquaterniônicas, que são um tipo especial de álgebra central simples de dimensão 16, obtida como produto tensorial de duas álgebras de quatérnios. A teoria de formas quadráticas é aplicada para estudarmos critérios de decisão sobre quando uma álgebra biquaterniônica é de divisão e quando duas destas álgebras são isomorfas. Além disso, utilizamos o u-invariante do corpo para discutirmos a existência de álgebras biquaterniônicas de divisão sobre o corpo. Provamos também um resultado atribuído a A. A. Albert, que estabelece critérios para decidir quando uma álgebra central simples de dimensão 16 é de fato uma álgebra biquaterniônica, através do estudo de involuções. Ao longo do trabalho, construímos vários exemplos concretos de álgebras biquaterniônicas satisfazendo propriedades importantes
Mestrado
Algebra
Mestre em Matemática

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Santos, Duilio Ferreira. "Elementos da teoria algébrica das formas quadráticas e de seus anéis graduados." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/45/45131/tde-22062016-104927/.

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Neste trabalho procuramos realizar uma apresentação autocontida sobre os conceitos da teoria algébrica de formas quadráticas e sobre os anéis graduados que surgiram no desenvolvimento desta teoria. Iniciamos procurando esclarecer o sentido da equivalência entre as várias acepções do conceito de forma quadrática. Após a apresentação de ingredientes e resultados geométricos, fazemos um extrato da teoria dos anéis de Witt, conceito que originou a moderna teoria algébrica de formas quadráticas. Disponibilizamos os elementos fundamentais para a formulação das teorias de cohomologia, nos concentrado no desenvolvimento da teoria de cohomologia profinita e, sobretudo, galoisiana. Descrevemos os funtores K0, K1 e K2 da K-teoria clássica e também a K-teoria de Milnor, que é mais adequada para formular questões sobre formas quadráticas. Finalizamos o trabalho com a apresentação de alguns conceitos da Teoria dos Grupos Especiais, uma codificação em primeira-ordem da teoria algébrica das formas quadráticas e exemplificamos sua importância, fornecendo um extrato da prova realizada por Dickmann-Miraglia da conjectura de Marshall sobre assinaturas, que se baseia fortemente nesta teoria.
In this work I try to provide a self-contained presentation on the concepts of algebraic theory of quadratic forms and on the graded rings that have emerged in the development of this theory. I started trying to clarify the meaning of \"equivalence\"between the various meanings of the concept of quadratic form. After the presentation of geometrical ingredients and results, we make an extract of the theory of Witt rings, a concept that originated the modern algebraic theory of quadratic forms. It is provided the key elements for the formulation of cohomology theories, focusing on the development of profinite cohomology theory and, especially, on galoisian cohomology. Are described the functors K0, K1 and K2 of classical K-theory and also the Milnor K-theory, which is more appropriate to formulate questions about quadratic forms. The dissertation is finished with the presentation of some concepts of the Theory of Special Groups, a first-order encoding of algebraic theory of quadratic forms, and with an example its importance by providing an extract of proof by Dickmann-Miraglia of the Marshalls conjecture on signatures, which relies heavily on this theory.

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Izquierdo, Diego. "Dualité et principe local-global sur les corps de fonctions." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS345/document.

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Dans cette thèse, nous nous intéressons à l'arithmétique de certains corps de fonctions. Nous cherchons à établir dans un premier temps des théorèmes de dualité arithmétique sur ces corps, pour les appliquer ensuite à l'étude des points rationnels sur certaines variétés algébriques. Dans les trois premiers chapitres, nous travaillons sur le corps des fonctions d'une courbe sur un corps local supérieur (comme Qp, Qp((t)), C((t)) ou C((t))((u))). Dans le premier chapitre, nous établissons sur un tel corps des théorèmes de dualité arithmétique « à la Poitou-Tate » pour les modules finis, les tores, et même pour certains complexes de tores. Nous montrons aussi l'existence, sous certaines hypothèses, de certaines portions des suites exactes de Poitou-Tate correspondantes. Ces résultats sont appliqués dans le deuxième chapitre à l'étude du principe local-global pour les algèbres simples centrales, de l'approximation faible pour les tores, et des obstructions au principe local-global pour les torseurs sous des groupes linéaires connexes. Dans le troisième chapitre, nous nous penchons sur les variétés abéliennes et établissons des théorèmes de dualité arithmétique « à la Cassels-Tate ». Cela demande aussi de mener une étude fine des variétés abéliennes sur les corps locaux supérieurs. Dans le quatrième et dernier chapitre, nous travaillons sur les corps des fractions de certaines algèbres locales normales de dimension 2 (typiquement C((x, y)) ou Fp((x, y))). Nous établissons d'abord un théorème de dualité en cohomologie étale « à la Artin-Verdier » dans ce contexte. Cela nous permet ensuite de montrer des théorèmes de dualité arithmétique en cohomologie galoisienne « à la Poitou-Tate » pour les modules finis et les tores. Nous appliquons finalement ces résultats à l'étude de l'approximation faible pour les tores et des obstructions au principe local-global pour les torseurs sous des groupes linéaires connexes
In this thesis, we are interested in the arithmetic of some function fields. We first want to establish arithmetic duality theorems over those fields, in order to apply them afterwards to the study of rational points on algebraic varieties. In the first three chapters, we work on the function field of a curve defined over a higher-dimensional local field (such as Qp, Qp((t)), C((t)) or C((t))((u))). In the first chapter, we establish "Poitou-Tate type" arithmetic duality theorems over such fields for finite modules, tori and even some complexes of tori. We also prove the existence, under some hypothesis, of parts of the corresponding Poitou-Tate exact sequences. These results are applied in the second chapter to the study of the local-global principle for central simple algebras, of weak approximation for tori, and of obstructions to local-global principle for torsors under connected linear algebraic groups. In the third chapter, we are interested in abelian varieties and we establish "Cassels-Tate type" arithmetic duality theorems. To do so, we also need to carry out a precise study of abelian varieties over higher-dimensional local fields. In the fourth and last chapter, we work on the field of fractions of some 2-dimensional normal local algebras (such as C((x, y)) or Fp((x, y))). We first establish in this context an "Artin-Verdier type" duality theorem in étale cohomology. This allows us to prove "Poitou-Tate type" arithmetic duality theorems in Galois cohomology for finite modules and tori. In the end, we apply these results to the study of weak approximation for tori and of obstructions to local-global principle for torsors under connected linear algebraic groups

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Wu, ping-ta, and 吳秉達. "The structure of Galois rings and the structure of finite local rings." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/21978780360538928711.

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碩士
國立中正大學
數學系研究所
105
We want to study the structure of Galois rings and analyze the unit of the Galois rings. And we will show that each finite commutative ring can be considered as a suitable algebra over a fixed Galois ring.

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Lodh, Rémi Shankar [Verfasser]. "Galois cohomology of Fontaine rings / vorgelegt von Rémi Shankar Lodh." 2007. http://d-nb.info/984696563/34.

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Katz, Daniel Jerome. "On p-Adic Estimates of Weights in Abelian Codes over Galois Rings." Thesis, 2005. https://thesis.library.caltech.edu/2329/1/djkatz_thesis.pdf.

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Let p be a prime. We prove various analogues and generalizations of McEliece's theorem on the p-divisibility of weights of words in cyclic codes over a finite field of characteristic p. Here we consider Abelian codes over various Galois rings. We present four new theorems on p-adic valuations of weights. For simplicity of presentation here, we assume that our codes do not contain constant words.

The first result has two parts, both concerning Abelian codes over Z/p^dZ. The first part gives a lower bound on the p-adic valuations of Hamming weights. This bound is shown to be sharp: for each code, we find the maximum k such that p^k divides all Hamming weights. The second part of our result concerns the number of occurrences of a given nonzero symbol s ∈ Z/p^dZ in words of our code; we call this number the s-count. We find a j such that p^j divides the s-counts of all words in the code. Both our bounds are stronger than previous ones for infinitely many codes.

The second result concerns Abelian codes over Z/4Z. We give a sharp lower bound on the 2-adic valuations of Lee weights. It improves previous bounds for infinitely many codes.

The third result concerns Abelian codes over arbitrary Galois rings. We give a lower bound on the p-adic valuations of Hamming weights. When we specialize this result to finite fields, we recover the theorem of Delsarte and McEliece on the p-divisibility of weights in Abelian codes over finite fields.

The fourth result generalizes the Delsarte-McEliece theorem. We consider the number of components in which a collection c_1,...,c_t of words all have the zero symbol; we call this the simultaneous zero count. Our generalized theorem p-adically estimates simultaneous zero counts in Abelian codes over finite fields, and we can use it to prove the theorem of N. M. Katz on the p-divisibility of the cardinalities of affine algebraic sets over finite fields.

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Procházková, Zuzana. "Význačné prvky grupových okruhů." Master's thesis, 2021. http://www.nusl.cz/ntk/nusl-448402.

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Title: Distinguished elements of group rings Author: Bc. Zuzana Procházková Department: Department of Algebra Supervisor: doc. Mgr. et Mgr. Jan Žemlička, Ph.D., Department of Algebra Abstract: This thesis is about finding idempotents in a group ring. We describe three techniques of finding idempotents in a semisimple group ring and in the last chapter there is an attempt to find idempotents in a group ring that does not have to be semisimple. The first technique uses representations and characters of a group. The second technique finds idempotents through the use of Shoda pairs. The third technique lifts idempotent from the factor ring with the help of CNC system of ideals, which is a generalization of a well-known technique with nilpotent ideals, and it is here extended to group rings formed by non-abelian group and noncommutative ring. iii

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Hammond, John Lockwood. "Regular realizations of p-groups." 2008. http://hdl.handle.net/2152/18100.

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Abstract:

This thesis is concerned with the Regular Inverse Galois Problem for p-groups over fields of characteristic unequal to p. Building upon results of Saltman, Dentzer characterized a class of finite groups that are automatically realized over every field, and proceeded to show that every group of order dividing p⁴ belongs to this class. We extend this result to include groups of order p⁵, provided that the base field k contains the p³-th roots of unity. The proof involves reducing to certain Brauer embedding problems defined over the rational function field k(x). Through explicit computation, we describe the cohomological obstructions to these embedding problems. Then by applying results about the Brauer group of a Dedekind domain, we show that they all possess solutions.
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Dissertations / Theses on the topic 'Galois ring'

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