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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

Relating Khovanov homology to a diagramless homology

McDougall, Adam Corey 01 July 2010 (has links)
A homology theory is defined for equivalence classes of links under isotopy in the 3-sphere. Chain modules for a link L are generated by certain surfaces whose boundary is L, using surface signature as the homological grading. In the end, the diagramless homology of a link is found to be equal to some number of copies of the Khovanov homology of that link. There is also a discussion of how one would generalize the diagramless homology theory (hence the theory of Khovanov homology) to links in arbitrary closed oriented 3-manifolds.
12

Subvariedades de ângulo constante em 3-variedades homogêneas / Constant angle submanifolds in homogeneous 3-manifolds

Aline de Moraes Teixeira 23 March 2015 (has links)
Um resultado clássico enunciado por M.A. Lancret em 1802 e provado por B. de Saint Venant em 1845 é: uma condição necessária e suficiente para que uma curva forme um ângulo constante com respeito a um campo de Killing unitário de R3 é que a razão entre a curvatura e a torção seja constante. Curvas deste tipo são chamadas hélices generalizadas. O problema de Lancret-de Saint Venant foi generalizado para curvas em outras variedades de dimensão três como, por exemplo, as formas espaciais e os grupos de Lie. Outra maneira de generalizar o estudo anterior é passar de curvas para superfícies, ou seja estudar as superfícies orientadas de 3-variedades Riemannianas cuja normal unitária faz um ângulo constante com certos campos de vetores privilegiados do espaço ambiente. Nesta dissertação estudaremos os resultados obtidos em [16, 24, 26, 27] sobre a classificação de curvas e superfícies de ângulo constante nas seguintes 3-variedades homogêneas: R3, o grupo de Heisenberg tridimensional e as esferas de Berger. / A classical result stated by M.A. Lancret in 1802 and first proved by B. de Saint Venant in 1845 is: a necessary and sufficient condition in order to a curve makes a constant angle with respect a unit Killing vector field of R3 is that the ratio of curvature to torsion be constant. Such curves are called general helix. The problem of Lancret-de Saint Venant has been generalized to curves in other three-dimensional manifolds as, for example, the space forms and the Lie groups. Another way to generalize the previous study is to pass from curves to surfaces, i.e. to study the oriented surfaces of Riemannian 3-manifolds for which the unit normal makes a constant angle with favored vector fields of the ambient space. In this dissertation we will study the results obtained in [16, 24, 26, 27] about the classification of constant angle curves and surfaces in the following homogeneous 3-manifolds: R3, the three-dimensional Heisenberg group and the Berger sphere.
13

BLINK : a language to view; Recognize; Classify and manipulate 3D-spaces

Didier Lins, Lauro January 2007 (has links)
Made available in DSpace on 2014-06-12T18:28:51Z (GMT). No. of bitstreams: 2 arquivo4264_1.pdf: 8529909 bytes, checksum: 0a958aa0c57b9a6b54d2a7542dbf9476 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Um blink é um grafo plano onde cada aresta ou é vermelha ou é verde. Um espaço 3D ou, simplesmente, um espaço é uma variedade 3-dimensional conexa, fechada e orientada. Neste trabalho exploramos pela primeira vez em maiores detalhes o fato de que todo blink induz um espaço e todo espaço é induzido por algum blink (na verdade por infinitos blinks). Qual o espaço de um triângulo verde? E de um quadrado vermelho? São iguais? Estas perguntas foram condensadas numa pergunta cuja busca pela resposta guiou em grande parte o trabalho desenvolvido: quais são todos os espaços induzidos por blinks pequenos (poucas arestas)? Nesta busca lançamos mão de um conjunto de ferramentas conhecidas: os blackboard framed links (BFL), os grupos de homologia, o invariante quântico de Witten-Reshetikhin-Turaev, as 3-gems e sua teoria de simplificação. Combinamos a estas ferramentas uma teoria nova de decomposição/composição de blinks e, com isso, conseguimos identificar todos os espaços induzidos por blinks de até 9 arestas (ou BFLs de até 9 cruzamentos). Além disso, o nosso esforço resultou também num programa interativo de computador chamado BLINK. Esperamos que ele se mostre útil no estudo de espaços e, em particular, na descoberta de novos invariantes que complementem o invariante quântico resolvendo as duas incertezas deixadas em aberto neste trabalho
14

Taut foliations, positive braids, and the L-space conjecture:

Krishna, Siddhi January 2020 (has links)
Thesis advisor: Joshua E. Greene / We construct taut foliations in every closed 3-manifold obtained by r-framed Dehn surgery along a positive 3-braid knot K in S^3, where r < 2g(K)-1 and g(K) denotes the Seifert genus of K. This confirms a prediction of the L--space conjecture. For instance, we produce taut foliations in every non-L-space obtained by surgery along the pretzel knot P(-2,3,7), and indeed along every pretzel knot P(-2,3,q), for q a positive odd integer. This is the first construction of taut foliations for every non-L-space obtained by surgery along an infinite family of hyperbolic L-space knots. We adapt our techniques to construct taut foliations in every closed 3-manifold obtained along r-framed Dehn surgery along a positive 1-bridge braid, and indeed, along any positive braid knot, in S^3, where r < g(K)-1. These are the only examples of theorems producing taut foliations in surgeries along hyperbolic knots where the interval of surgery slopes is in terms of g(K). / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.
15

Wild Low-Dimensional Topology and Dynamics

Meilstrup, Mark H. 02 June 2010 (has links)
In this dissertation we discuss various results for spaces that are wild, i.e. not locally simply connected. We first discuss periodic properties of maps from a given space to itself, similar to Sharkovskii's Theorem for interval maps. We study many non-locally connected spaces and show that some have periodic structure either identical or related to Sharkovskii's result, while others have essentially no restrictions on the periodic structure. We next consider embeddings of solenoids together with their complements in three space. We differentiate solenoid complements via both algebraic and geometric means, and show that every solenoid has an unknotted embedding with Abelian fundamental group, as well as infinitely many inequivalent knotted embeddings with non-Abelian fundamental group. We end by discussing Peano continua, particularly considering subsets where the space is or is not locally simply connected. We present reduced forms for homotopy types of Peano continua, and provide a few applications of these results.
16

Dehn surgery on knots in the Poincaré homology sphere:

Caudell, Jacob January 2023 (has links)
Thesis advisor: Joshua E. Greene / We develop and implement obstructions to realizing a 3-manifold all of whose prime summands are lens spaces as Dehn surgery on a knot K in the Poincaré homology sphere, and in the process, we determine the knot Floer homology groups of a knot with such a surgery. We show that such a surgery never results in a 3-manifold with more than three non-trivial summands, and that if the result of surgery has exactly three non-trivial summands, then K is isotopic to a regular Seifert fiber. We furthermore identify the only two knots with half-integer lens space surgeries, and thus complete the classification of knots in the Poincaré homology sphere with non-integer lens space surgeries. We lastly show that a lens space L(p, q) that is realized as integer surgery on a knot K is realized as integer surgery on a Tange knot when p ≥ 2g(K). In order to do so, we build on Greene’s work on changemaker lattices and develop the theory of E8-changemaker lattices. / Thesis (PhD) — Boston College, 2023. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.
17

TQFTs from Quasi-Hopf Algebras and Group Cocycles

George, Jennifer Lynn 27 August 2013 (has links)
No description available.
18

A Toolkit for the Construction and Understanding of 3-Manifolds

Lambert, Lee R. 13 July 2010 (has links) (PDF)
Since our world is experienced locally in three-dimensional space, students of mathematics struggle to visualize and understand objects which do not fit into three-dimensional space. 3-manifolds are locally three-dimensional, but do not fit into 3-dimensional space and can be very complicated. Twist and bitwist are simple constructions that provide an easy path to both creating and understanding closed, orientable 3-manifolds. By starting with simple face pairings on a 3-ball, a myriad of 3-manifolds can be easily constructed. In fact, all closed, connected, orientable 3-manifolds can be developed in this manner. We call this work a tool kit to emphasize the ease with which 3-manifolds can be developed and understood applying the tools of twist and bitwist construction. We also show how two other methods for developing 3-manifolds–Dehn surgery and Heegaard splitting–are related to the twist and bitwist construction, and how one can transfer from one method to the others. One interesting result is that a simple bitwist construction on a 3-ball produces a group of manifolds called generalized Sieradski manifolds which are shown to be a cyclic branched cover of S^3 over the 2-braid, with the number twists determined by the hemisphere subdivisions. A slight change from bitwist to twist causes the knot to become a generalized figure-eight knot.
19

Comparing Invariants of 3-Manifolds Derived from Hopf Algebras

Sequin, Matthew James 27 June 2012 (has links)
No description available.
20

Enhancing the Quandle Coloring Invariant for Knots and Links

Cho, Karina Elle 01 January 2019 (has links)
Quandles, which are algebraic structures related to knots, can be used to color knot diagrams, and the number of these colorings is called the quandle coloring invariant. We strengthen the quandle coloring invariant by considering a graph structure on the space of quandle colorings of a knot, and we call our graph the quandle coloring quiver. This structure is a categorification of the quandle coloring invariant. Then, we strengthen the quiver by decorating it with Boltzmann weights. Explicit examples of links that show that our enhancements are proper are provided, as well as background information in quandle theory.

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