In his seminal work on modular curves and the Eisenstein ideal, Mazur studied the existence of congruences between certain Eisenstein series and newforms, proving that Eisenstein ideals associated to weight 2 cusp forms of prime level are locally principal. In this dissertation, we re-examine Eisenstein congruences, incorporating a notion of “depth of congruence,” in order to understand the local structure of Eisenstein ideals associated to weight 2 cusp forms of squarefree level N. Specifically, we use a commutative algebra result of Berger, Klosin, and Kramer to bound the depth of mod p Eisenstein congruences (from below) by the p-adic valuation of φ(N). We then show how this depth of congruence controls the local principality of the associated Eisenstein ideal.

Made available in DSpace on 2015-04-09T12:28:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-28Bitstream added on 2015-04-09T12:47:25Z : No. of bitstreams: 1 000811533.pdf: 482329 bytes, checksum: 0976b8826895590ad47ec9f1a4f95e20 (MD5) / O objetivo principal desse trabalho é estudar o conceito de congruência por corte de polígonos e poliedros. Primeiro é apresentado o teorema de Bolyai-Gerwien que afirma a equivalência entre a igualdade de área e congruência por corte de polígonos. No caso de poliedros é apresentado o teorema de Dehn no qual veremos que a congruência por corte e a igualdade de volumes, em geral, não são equivalentes. No final serão apresentadas algumas atividades onde se pode verificar de maneira intuitiva e dedutiva a congruência por corte entre alguns polígonos com a mesma área / The main object of this work is study some elementary comcepts in Euclidean geometry. After studying the scissors-congruence between polygons, we prove the Bolayi-Gerwein theorem. We study also this concept for polyhedra and we see the Dehn theorem which claims that in the case of polyhedra the equality between the volume and the scissors-congruence are not equivalent in general. Finally, we present some activities where it is possible to check by an intuitive and a deductive manner the congruence by cutting between some polygons with the same area

Orientador: Parham Salehyan / Banca: Ali Tahzibi / Banca: Luciana de Fátima Martins / O PROFMAT - Programa de Mestrado Profissional em Matemática em Rede Nacional é coordenado pela Sociedade Brasileira de Matemática e realizado por uma rede de Instituições de Ensino Superior. / Resumo: O objetivo principal deste trabalho é provar o Teorema de Dehn. Esse teorema é resposta ao Terceiro Problema de Hilbert, este problema refere-se à seguinte situação: Se dois poliedros possuem o mesmo volume eles são congruentes por corte, ou seja, é sempre possível tomar dois poliedros de mesmo volume e decompor um em poliedros menores de tal maneira que os reorganizando seja possível montar o outro. A resposta para esta questão é negativa e sua prova ficou conhecida como teorema de Dehn. Inicialmente estudaremos conceitos de área, volume e congruência por corte para figuras planas e no espaço. Nesta etapa discutiremos a decomposição de figuras em polígonos e poliedros. Em seguida usando algumas propriedades de funções aditivas e os ângulos diedros de um poliedro, construiremos um invariante que será a ferramenta principal na demonstração do Teorema de Dehn. Como considerações finais, cito o Paradoxo de Banach-Tarski, uma vez que o mesmo é relacionado naturalmente ao problema de congruência por corte e decomposição de figuras no espaço e apresento um capítulo com algumas atividades que podem ser desenvolvidas na educação básica / Abstract: The main object of this work is study the Third Problem of Hilbert and the Dehn Theorem / Mestre

O presente trabalho inicia-se com uma breve história sobre a evolução da Teoria dos Números, destacando os estudiosos que tiveram grande importância para o reconhecimento dessa parte da Matemática. Logo após, é feita uma fundamentação teórica dos principais tópicos da Teoria dos Números, ressaltando alguns teoremas e apresentando exemplos de aplicações em várias áreas da Matemática. É apresentado um estudo a respeito dos diversos sistemas de codificação que fazem o uso do dígito verificador, com o objetivo de motivar o aluno a entender um pouco sobre o conceito de aritmética modular, de maneira fácil, rápida e simples. Para finalizar são apresentados relatos de atividades realizadas com alunos do ensino básico, envolvendo códigos de barras, visando ressaltar a importância de entender a aplicabilidade das congruências nos dias de hoje. / His work starts by describing a brief history on the development of Numbers Theory, highlighting the ones who had great importance for the recognition of this part of Mathematics. Next, a theoretical framework of the main topics of Numbers Theory is made, emphasizing some theorems and presenting examples of applications in several areas of Mathematics. A survey is done about several coding systems that use check digit, in order to motivate the student to understand the concept of modular arithmetic, in an easy, fast and simple way. Finally, we present reports of activities carried out with students of basic education, involving bar codes, in order to highlight the importance of understanding the applicability of congruences nowadays.

We give congruences modulo powers of 2 for the Fourier coefficients of certain level 2 modular functions with poles only at 0, answering a question posed by Andersen and Jenkins. The congruences involve a modulus that depends on the binary expansion of the modular form's order of vanishing at infinity. We also demonstrate congruences for Fourier coefficients of some level 4 modular functions.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 431-432). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 431-432). Also available on the Internet.

O presente trabalho inicia-se com uma breve história sobre a evolução da Teoria dos Números, destacando os estudiosos que tiveram grande importância para o reconhecimento dessa parte da Matemática. Logo após, é feita uma fundamentação teórica dos principais tópicos da Teoria dos Números, ressaltando alguns teoremas e apresentando exemplos de aplicações em várias áreas da Matemática. É apresentado um estudo a respeito dos diversos sistemas de codificação que fazem o uso do dígito verificador, com o objetivo de motivar o aluno a entender um pouco sobre o conceito de aritmética modular, de maneira fácil, rápida e simples. Para finalizar são apresentados relatos de atividades realizadas com alunos do ensino básico, envolvendo códigos de barras, visando ressaltar a importância de entender a aplicabilidade das congruências nos dias de hoje. / His work starts by describing a brief history on the development of Numbers Theory, highlighting the ones who had great importance for the recognition of this part of Mathematics. Next, a theoretical framework of the main topics of Numbers Theory is made, emphasizing some theorems and presenting examples of applications in several areas of Mathematics. A survey is done about several coding systems that use check digit, in order to motivate the student to understand the concept of modular arithmetic, in an easy, fast and simple way. Finally, we present reports of activities carried out with students of basic education, involving bar codes, in order to highlight the importance of understanding the applicability of congruences nowadays.

Discrete Differential Geometry (DDG) concerns discrete counterparts of notions and methods in differential geometry. This thesis deals with a core subject in DDG, discrete curvature theories on various types of polyhedral surfaces that are practically important for free-form architecture, sunlight-redirecting shading systems, and face recognition. Modeled as polyhedral surfaces, the shapes of free-form structures may have to satisfy different geometric or physical constraints. We study a combination of geometry and physics – the discrete surfaces that can stand on their own, as well as having proper shapes for the manufacture. These proper shapes, known as circular and conical meshes, are closely related to discrete principal curvatures. We study curvature theories that make such surfaces possible. Shading systems of freeform building skins are new types of energy-saving structures that can re-direct the sunlight. From these systems, discrete line congruences across polyhedral surfaces can be abstracted. We develop a new curvature theory for polyhedral surfaces equipped with normal congruences – a particular type of congruences defined by linear interpolation of vertex normals. The main results are a discussion of various definitions of normality, a detailed study of the geometry of such congruences, and a concept of curvatures and shape operators associated with the faces of a triangle mesh. These curvatures are compatible with both normal congruences and the Steiner formula. In addition to architecture, we consider the role of discrete curvatures in face recognition. We use geometric measure theory to introduce the notion of asymptotic cones associated with a singular subspace of a Riemannian manifold, which is an extension of the classical notion of asymptotic directions. We get a simple expression of these cones for polyhedral surfaces, as well as convergence and approximation theorems. We use the asymptotic cones as facial descriptors and demonstrate the practicability and accuracy of their applications in face recognition.

As shown by Zagier, singular moduli can be represented by the coefficients of a certain half integer weight modular form. Congruences for singular moduli modulo arbitrary primes have been proved by Ahlgren and Ono, Edixhoven, and Jenkins. Computation suggests that stronger congruences hold for small primes $p \in \{2, 3, 5, 7, 11\}$. Boylan proved stronger congruences hold in the case where $p=2$. We conjecture congruences for singular moduli modulo powers of $p \in \{3, 5, 7, 11\}$. In particular, we study the case where $p=3$ and reduce the conjecture to a congruence for a simpler modular form.