Orientador: Dessislava Hristova Kochloukova / Dissertação (mestrado) - Universidade Estadual de Campinas. Instituto de Matematica, Estatistica e Computação Científica / Made available in DSpace on 2018-08-04T04:02:42Z (GMT). No. of bitstreams: 1 Silva_VivianeMorettoda_M.pdf: 772022 bytes, checksum: df78c072210885081ecac3c1e89b04fd (MD5) Previous issue date: 2005 / Resumo: Nesta dissertação de mestrado, estudamos propriedades de álgebras de Lie. As Álgebras de Lie têm grande importância nao somente na teoria de álgebras não associativas, elas surgem também em geometria, topologia e no estudo da teoria de grupos por exemplo. As definições e resultados básicos sobre álgebras de Lie estão inclusos no Capítulo 2. Para esta parte do trabalho, utilizamos os livros [1] e [2]. O nosso enfoque foi sobre álgebras universais envelopantes, mergulhando assim a álgebra de Lie em álgebras associativas (Seções 2.4, 2.5 e 2.6). O objetivo principal da dissertação foi estudar o artigo [4], ¿Finite presentation of abelian-by-finite dimensional Lie algebras¿, que classifica álgebras de Lie finitamente apresentáveis (no sentido de serem definidas por número finito de geradores e relações) que são extensões de ideal abeliano por álgebra de Lie de dimensão finita. Definimos álgebras de Lie livres na seção 2.7.Tratam-se de objetos na categoria de álgebras de Lie que satisfazem propriedade universal semelhante a definição de grupos livres. A classificação de álgebras de Lie que são extensões de ideal abeliano por álgebra de Lie de dimensão finita usa teoria de módulos Noetherianos. No Capítulo 1 incluímos resultados básicos sobre módulos, em particular estudamos módulos Noetherianos, não necessariamente sobre anéis comutativos (para este estudo utilizamos [9]), embora alguns resultados sejam válidos somente no caso onde o anel básico é comutativo (caso do Teorema da Base de Hilbert 1.31 no Capítulo 1). No final, nos Capítulos 3 e 4, explicamos de maneira bem minuciosa (com mais 6 detalhes que o original) o resultado principal de [4], que 'e apresentado na página 42: Proposicão 3.2: Seja L uma álgebra de Lie finitamente gerada sobre o corpo K. Suponha que L tenha um ideal abeliano A tal que L/A tem dimensão finita como espaço vetorial. Seja R álgebra universal envelopante de L/A. Suponha também que o quadrado tensorial A X A é finitamente gerado como R-módulo sobre a ação diagonal. Então L é finitamente apresentável. Os métodos da demonstração de 3.2 envolvem muitos cálculos com relações em L para mostrar que um conjunto finito E 'e suficiente para gerar todas as relações em L. Embora os cálculos sejam muitos, a técnica principal 'e a indução e a Identidade de Jacobi. A teoria de módulos Noetherianos também foi muito utilizada / Abstract: In this work we study the classification of finitely presented abelian-by-finite dimensional Lie algebras given in [4]. If L is a Lie algebra, an extension of an abelian ideal A by a finite dimensional Lie algebra L/A then L is finitely presented if and only if A X A is finitely generated as U(L/A)-module via the diagonal action, where U(L/A) is the universal enveloping algebra of L/A. We study in detail the result that finite generation of A X A over U(L/A) implies finite presentability of L / Mestrado / Matematica / Mestre em Matemática

This thesis consists of four papers on the topics of free loop spaces, Koszul duality and A∞-algebras.  In Paper I we consider a definition of differential operators for noncommutative algebras. This definition is inspired by the connections between differential operators of commutative algebras, L∞-algebras and BV-algebras. We show that the definition is reasonable by establishing results that are analoguous to results in the commutative case. As a by-product of this definition we also obtain definitions for noncommutative versions of Gerstenhaber and BV-algebras.  In Paper II we calculate the free loop space homology of (n-1)-connected manifolds of dimension of at least 3n-2. The Chas-Sullivan loop product and the loop bracket are calculated. Over a field of characteristic zero the BV-operator is determined as well. Explicit expressions for the Betti numbers are also established, showing that they grow exponentially.  In Paper III we restrict our coefficients to a field of characteristic 2. We study the Dyer-Lashof operations that exist on free loop space homology in this case. Explicit calculations are carried out for manifolds that are connected sums of products of spheres.  In Paper IV we extend the Koszul duality methods used in Paper II by incorporating A∞-algebras and A∞-coalgebras. This extension of Koszul duality enables us to compute free loop space homology of manifolds that are not necessarily formal and coformal. As an example we carry out the computations for a non-formal simply connected 7-manifold. / Denna avhandling består av fyra artiklar inom ämnena fria öglerum, Koszuldualitet och A∞-algebror. I Artikel I behandlar vi en definition av differentialoperatorer för ickekommutativa algebror. Denna definition är inspirerad av kopplingar mellan differentialoperatorer för kommutativa algebror, L∞-algebror och BV-algebror. Vi visar att definitionen är rimlig genom att etablera resultat som är analoga med resultat i det kommutativa fallet. Som en biprodukt får vi också definitioner för ickekommutativa varianter av Gerstenhaber och BV-algebror. I Artikel II beräknar vi den fria öglerumshomologin av (n-1)-sammanhängande mångfalder av dimension minst 3n-2. Chas-Sullivans ögleprodukt och öglehake beräknas. Över en kropp av karakteristik noll beräknas även BV-operatorn. Explicita uttryck för Bettitalen fastställs också, vilka visar att de växer exponentiellt. I Artikel III begränsar vi koefficienterna till en kropp av karakteristik 2. Vi studerar Dyer- Lashofoperationer som existerar på den fria öglerumshomologin i detta fall. Explicita beräkningar görs för mångfalder som är sammanhängande summor av produkter av sfärer. I Artikel IV utvidgar vi Koszuldualitetmetoden som används i Artikel II genom att inkorporera A∞-algebror och A∞-koalgebror. Denna utvidgning av Koszuldualitet gör det möjligt att beräkna fri öglerumshomologi för mångfalder som inte nödvändigtvis är formella och koformella. Som ett exempel utför vi beräkningar för en ickeformell enkelt sammanhängande 7-mångfald. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>

To the pair (E,c), where E is a countable Borel equivalence relation on a standard Borel space (X,A) and c a normalized Borel T-valued 2-cocycle on E, we associate a sequentially weakly closed Borel *-algebra Br*(E,c), contained in the bounded linear operators on L^2(E). Associated to Br*(E,c) is a natural (Borel) Cartan subalgebra (Definition 6.4.10) L(Bo(X)) isomorphic to the bounded Borel functions on X. Then L(Bo(X)) and its normalizer (the set of the unitaries u in Br*(E,c) such that u*fu in L(Bo(X)), f in L(Bo(X))) countably generates the Borel *-algebra Br*(E,c). In this thesis, we study Br*(E,c) and in particular prove that: i) If E is smooth, then Br*(E,c) is a type I Borel *-algebra (Definition 6.3.10). ii) If E is a hyperfinite, then Br*(E,c) is a Borel AF-algebra (Definition 7.5.1). iii) Generalizing Kumjian's definition, we define a Borel twist G over E and its associated sequentially closed Borel *-algebra Br*(G). iv) Let a Borel Cartan pair (B, Bo) denote a sequentially closed Borel *-algebra B with a Borel Cartan subalgebra Bo, where B is countably Bo-generated. Generalizing Feldman-Moore's result, we prove that any pair (B, Bo) can be realized uniquely as a pair (Br*(E,c), L(Bo(X))). Moreover, we show that the pair (Br*(E,c), L(Bo(X))) is a complete invariant of the countable Borel equivalence relation E. v) We prove a Krieger type theorem, by showing that two aperiodic hyperfinite countable equivalence relations are isomorphic if and only if their associated Borel *-algebras Br*(E1) and Br*(E2) are isomorphic.

Orientador: Adriano Adrega de Moura / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-22T08:28:52Z (GMT). No. of bitstreams: 1 Calixto_LucasHenrique_M.pdf: 1707951 bytes, checksum: a7576ec9f19a4faf6e8bd959192baeb8 (MD5) Previous issue date: 2013 / Resumo: O principal objetivo dessa dissertação é explicar a classificação dos módulos irredutíveis de dimensão finita para qualquer super álgebra de funções sobre uma super álgebra de Lie básica. Os principais resultados dizem que um módulo irredutível de dimensão finita ou é uma representação de avaliação ou é um módulo de Kac para certo módulo de avaliação generalizado. Para chegar a tal objetivo, também fazemos uma revisão detalhada da classificação das super álgebras de Lie básicas / Abstract: The goal of this dissertation is to explain the classification of the irreducible finite-dimensional representations of a map superalgebra whose underlying simple Lie superalgebra is basic. The main result says that an irreducible finite-dimensional module is either an evaluation module or a Kac module associated to a certain generalized evaluation module. We also give a detailed review of the classification of the basic Lie superalgebras / Mestrado / Matematica / Mestre em Matemática

Orientador: Lucio Centrone / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-27T16:21:21Z (GMT). No. of bitstreams: 1 Lobo_MiqueiasdeMelo_M.pdf: 612489 bytes, checksum: 4f5b408cbd8a473c143ee07e289ce4fb (MD5) Previous issue date: 2015 / Resumo: Neste trabalho estudamos álgebras com identidades polinomiais. Mais especificamente, estudamos os principais teoremas de estrutura das PI-álgebras graduadas e entre eles a versão graduada do teorema de Posner, obtida por Balaba em 2005, que abriu o caminho para diversas aplicações importantes nos últimos anos / Abstract: In this work we study algebras with polynomial identities. More specifically, we study the main structure theorems for graded PI-algebras and including the graded version of Posner's theorem, obtained by Balaba in 2005, which paved the way for several important applications in recent years / Mestrado / Matematica / Mestre em Matemática

We generalize the results of Leger and Luks and other researchers about generalized derivations to the cases of ternary Lie algebras and n-BiHom Lie algebras. We investigate the derivations algebras of ternary Lie algebras induced from Lie algebras, we explore the subalgebra of quasi-derivations and give their properties. Moreover, we give a classification of the derivations algebras for low dimensional ternary Lie algebras. For the class of n-BiHom Lie algebras, we study the algebras of generalized derivations and prove that the algebra of quasi-derivations can be embedded in the derivation algebra of a larger n-BiHom Lie algebra.

The non-resonant bounded uniserial representations of Vec(R) form a certain class of extensions composed of tensor density modules, all of whose subquotients are indecomposable. The problem of classifying the extensions with a given composition series is reduced via cohomological methods to computing the solution of a certain system of polynomial equations in several variables derived from the cup equations for the extension. Using this method, we classify all non-resonant bounded uniserial extensions of Vec(R) up to length 6. Beyond this length, all such extensions appear to arise as subquotients of extensions of arbitrary length, many of which are explained by the psuedodifferential operator modules. Others are explained by a wedge construction and by the pseudodifferential operator cocycle discovered by Khesin and Kravchenko.

Quasidiagonality is a matricial approximation property which asymptotically captures the multiplicative structure of C* -algebras. Quasidiagonal C* -algebras must be stably finite. It has been conjectured by Blackadar and Kirchberg that stably finiteness implies quasidiagonality for the class of separable nuclear C* -algebras. It has also been conjectured that separable exact quasidiagonal C* -algebras are AF embeddable. In this thesis, we study the behavior of these conjectures in the context of extensions 0 → I → E → B → 0. Specifically, we show that if I is exact and connective and B is separable, nuclear, and quasidiagonal (AF embeddable), then E is quasidiagonal (AF embeddable). Additionally, we show that if I is of the form C(X) ⊗ K for a compact metrizable space X and B is separable, nuclear, quasidiagonal (AF embeddable), and satisfies the UCT, then E is quasidiagonal (AF embeddable) if and only if E is stably finite.

No description available.

This thesis aims to provide a classification of low-dimensional Lie algebras. We make emphasis on several structural properties, such as nilpotency, solvability and (semi) simpli- city. The first two properties relate to two fundamental theorems by Lie and Engels which classification results will be presented in a table for ease of access. / <p>I presented my thesis on 1st of October 2021.</p>