Este trabalho é um estudo de raízes para aplicações f : S → Wn, onde S é uma superfície compacta, conexa e sem bordo e Wn é o espaço obtido pela reunião em um ponto do círculo S1 com n esferas S2 . / The propose of this work is studies the root problem for maps f : S → Wn, where S is a closed, connected, compact surface and W n is the space obtained by the one point union of circle S1 and n spheres S2.

If X is a simply connected CW complex, then it has a unique (up to isomorphism) minimal Sullivan model. There is an important rational homotopy invariant, called the rational Lusternik–Schnirelmann of X, denoted cat0(X), which has an algebraic formulation in terms of the minimal Sullivan model of X. We study another such numerical invariant called the rational retraction index of X, denoted r0(X), which is defined in terms of the minimal Sullivan model of X and satisfies 0 ≤ r0(X) ≤ cat0(X). It was introduced by Cuvilliez et al. as a tool to estimate the rational Lusternik–Schnirelmann category of the total space of a fibration. In this thesis we compute the rational retraction index on a range of rationally elliptic spaces, including for example spheres, complex projective space, the biquotient Sp(1) \ Sp(3) / Sp(1) × Sp(1), the homogeneous space Sp(3)/U(3) and products of these. In particular, we focus on formal spaces and formulate a conjecture to answer a question posed in the original article of Cuvilliez et al., “If X is formal, what invariant of the algebra H∗(X;Q) is r0(X)?”

Two standard invariants used to study the fundamental group of the complement X of a hyperplane arrangement are the Malcev completion of its fundamental group G and the cohomology groups of X with coefficients in rank one local systems. In this thesis, we develop a tool that unifies these two approaches. This tool is the Malcev completion S_p of G relative to a homomorphism p from G into (C^*)^N. The relative completion S_p is a prosolvable group that generalizes the classical Malcev completion; when p is the trivial representation, S_p is the Malcev completion of G. The group S_p is tightly controlled by the cohomology groups H^1(X,L_{p^k}) with coefficients in the irreducible local systems L_{p^k} associated to the representation p.The pronilpotent Lie algebra u_p of the prounipotent radical U_p of S_p has been described by Hain. If p is the trivial representation, then u_p is the holonomy Lie algebra, which is well-known to be quadratically presented. In contrast, we show that when X is the complement of the braid arrangement in complex two-space, there are infinitely many representations p from G into (C^*)^2 for which u_p is not quadratically presented.We show that if Y is a subtorus of the character torus T containing the trivial character, then S_p is combinatorially determined for general p in Y. We do not know whether S_p is always combinatorially determined. If S_p is combinatorially determined for all characters p of G, then the characteristic varieties of the arrangement X are combinatorially determined.When Y is an irreducible subvariety of T^N, we examine the behavior of S_p as p varies in Y. We define an affine group scheme S_Y over Y such that if Y = {p}, then S_Y is the relative Malcev completion S_p. For each p in Y, there is a canonical homomorphism of affine group schemes from S_p into the affine group scheme which is the restriction of S_Y to p. This is often an isomorphism. For example, if there exists p in Y whose image is Zariski dense in G_m^N, then this homomorphism is an isomorphism for general p in Y. / Dissertation

Thesis--Princeton University. / Includes bibliographical references.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2010) Includes bibliographical references (p. 133-134).

of doctoral thesis "Computational Homotopy Theory": We consider several basic problems of algebraic topology, with connections to combinatorial and geometric questions, from the point of view of compu- tational complexity. The extension problem asks, given topological spaces X, Y , a subspace A ⊆ X, and a (continuous) map f : A → Y , whether f can be extended to a map X → Y . For computational purposes, we assume that A, X, Y are represented as finite simplicial complexes and f as a simplicial map. We study the problem under the assumption that, for some d ≥ 1, Y is d- connected, otherwise the problem is undecidable by uncomputability of the fundamental group; We prove that, this problem is still undecidable for dim X = 2d + 2. On the other hand, for every fixed dim X ≤ 2d + 1, we obtain an algorithm that solves the extension problem in polynomial time. We obtain analogous complexity results for the problem of determining the set of homotopy classes of maps X → Y . We also consider the computation of the homotopy groups πk(Y ), k ≥ 2, for a 1-connected Y . Their computability was established by Brown in 1957; we show that πk(Y ) can be computed in polynomial time for every fixed k ≥ 2. On the other hand, we prove that computing πk(Y ) is #P-hard if k is a part of input. It is a strengthening of...

Orientador: Alcibiades Rigas, Tomas Edson Barros / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-06T01:35:44Z (GMT). No. of bitstreams: 1 Hoefel_EduardoOuteiralCorrea_D.pdf: 1956293 bytes, checksum: 425e3f8509c6c6d5b7e71d692027dfaf (MD5) Previous issue date: 2006 / Resumo: Esta tese consiste do estudo das OCHAs (Open-Closed Homotopy Algebras) sob os pontos de vista algébrico e geométrico. São demonstrados essencialmente dois resultados novos. O primeiro refere-se à definição de OCHA através de coderivações. Mais especificamente, provamos que qualquer coderivação D E Coderl (sc'Hc 0 TC'Ho) de grau 1 satisfazendo D2 = O define uma estrutura de OCHA em 'H = 'Hcffi'Ho. Onde 'Hc e 'Ho são os espaços de estados da teoria de campo de corda para cordas fechadas ("dosed strings") e cordas abertas ("open strings"), respectivamente. Até então, sabia-se que as OCHAs eram dadas por coderivações [14], mas o fato de que qualquer coderivação define uma OCHA, é novo. O segundo resultado envolve a relação entre OCHA e a versão real da compactificação de Fulton MacPherson do espaço de configurações de pontos no semi-plano superior fechado. Este resultado mostra a estreita relação entre OCHAs e a operada do "Queijo Suíço" introduzida por Voronov [41], tal relação foi de fato sugeri da na introdução de [14]. O capítulo 1 contém uma discussão sobre a definição de OCHA usando coálgebras e a conseqüente caracterização das coderivações mencionada acima. Mostramos também que a estrutura de OCHA pode ser obtida a partir de certas álgebras A(X) de forma inteiramente análoga ao modo como álgebras de Lie podem ser obtidas a partir de álgebras associativas. Em seguida, o capítulo 2 traz a abordagem das OCHAs através de operadas. O capítulo 3 traz uma discussão detalhada do espaço C(p, q) (a compactificação de Fulton;.MacPherson do espaço de configurações de p + q pontos no semi-plano superior fechado com p pontos no interior e q pontos no bordo) e no capítulo 4 mostramos que a parte essencial da operada que descreve as OCHAs aparece na primeira linha do termo E1 da seqüência espectral induzida por aquele espaço. O resultado mencionado acima significa que a estrutura algébrica das OCHAs está codificada na estratificação do bordo da variedade C(p, q), visto que esta última tem uma estrutura de variedade com córneres. No capítulo final discutimos o significado dos dois resultados obtidos procurando fazer um paralelo entre as abordagens geométrica e algébrica e mencionamos alguns problemas interessantes, como continuação deste trabalho, que podem ser considerados por estudantes interessados em Álgebras Homotópicas e temas relacionados / Abstract: This thesis consists of the study of OCHA (Open-Closed Homotopy Algebras) from both the algebraic and geometric viewpoint. It essentially contains the proof of two new results. The first one is related to the definition of OCHA through coderivations. More specifically, it is shown that any degree one coderivation D E Caderl(Sc7íc 0 TC7ío) such that D2 = O defines an OCHA structure on 7í = 7íc E9 7ío. Where 7íc and 7ío are respectively the state spaces of Closed String Field Theory and apen String Field Theory. It was cIear since its definition in 2004 that OCHAs can be defined in terms of coderivations. Nevertheless, the fact that any such coderivation is of the OCHA form is new. The second result involves the relation between OCHA and the real version of the Fulton MacPherson compactification of the configuration space of points on the cIosed upper half-plane. That result shows the cIose relation between OCHAs and the Swiss-Cheese operad introduced by Voronov [411. Such relation was in fact suggested in the introductian of [141. Chapter 1 contains a discussion about the coalgebraic definition of OCHA and the above mentioned characterization of alI coderivations. It is also shown that OCHA can be obtained from certain A8 algebras, similarly to way in which Lie algebras are obtained fro_ associative algebras. Chapter 2 then shows how to approach OCHA using aperads. The space C(p, q) (the FuIton-MacPherson compactification of the configuration space of p + q points on the upper half-plane with p interior points and q boundary points) is discussed on chapter 3 and on chapter 4 it is shown that the essential part of the operad describing OCHA appears on the first line Of the spectral sequence induced by that space. In other words, we could say that the algebraic structure of OCHA is encoded in the stratification of C(p, q), since this space has the structure of a manifold with corners. The final chapter is a discussion about the meaning of the two mais results of this thesis. After that, some problems which could be explored by the student interested on homotopy algebras and related subjects are mentioned. / Doutorado / Geometria Topologia / Doutor em Matemática

Este trabalho é um estudo de raízes para aplicações f : S → Wn, onde S é uma superfície compacta, conexa e sem bordo e Wn é o espaço obtido pela reunião em um ponto do círculo S1 com n esferas S2 . / The propose of this work is studies the root problem for maps f : S → Wn, where S is a closed, connected, compact surface and W n is the space obtained by the one point union of circle S1 and n spheres S2.

If X is a simply connected CW complex, then it has a unique (up to isomorphism) minimal Sullivan model. There is an important rational homotopy invariant, called the rational Lusternik–Schnirelmann of X, denoted cat0(X), which has an algebraic formulation in terms of the minimal Sullivan model of X. We study another such numerical invariant called the rational retraction index of X, denoted r0(X), which is defined in terms of the minimal Sullivan model of X and satisfies 0 ≤ r0(X) ≤ cat0(X). It was introduced by Cuvilliez et al. as a tool to estimate the rational Lusternik–Schnirelmann category of the total space of a fibration. In this thesis we compute the rational retraction index on a range of rationally elliptic spaces, including for example spheres, complex projective space, the biquotient Sp(1) \ Sp(3) / Sp(1) × Sp(1), the homogeneous space Sp(3)/U(3) and products of these. In particular, we focus on formal spaces and formulate a conjecture to answer a question posed in the original article of Cuvilliez et al., “If X is formal, what invariant of the algebra H∗(X;Q) is r0(X)?”

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