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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.
1

Integral Linking para o espaço hiperbólico / Linkin integral to hyperbolic space

Souza, Geraldo Herbert Beltrão de January 2016 (has links)
SOUZA, Geraldo Herbert Beltrão de. Integral Linking para o espaço hiperbólico. 2016. 35 f. Dissertação (Mestrado em Matemática)- Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Rocilda Sales (rocilda@ufc.br) on 2016-09-19T15:13:15Z No. of bitstreams: 1 2016_dis_ghbsouza.pdf: 464546 bytes, checksum: a010067c092935c226c9771b9f96d399 (MD5) / Approved for entry into archive by Rocilda Sales (rocilda@ufc.br) on 2016-09-19T15:13:53Z (GMT) No. of bitstreams: 1 2016_dis_ghbsouza.pdf: 464546 bytes, checksum: a010067c092935c226c9771b9f96d399 (MD5) / Made available in DSpace on 2016-09-19T15:13:53Z (GMT). No. of bitstreams: 1 2016_dis_ghbsouza.pdf: 464546 bytes, checksum: a010067c092935c226c9771b9f96d399 (MD5) Previous issue date: 2016 / This research aimed to find a comprehensive formula that calculates the linking number between two submanifolds of a visible hypersurface of hyperbolic space, which will be defined in the text. The motivation for this was the article "HIGHER-DIMENSIONAL LINKING INTEGRALS " whose authors are Clayton Shonkwiler and David Shea Candle-Vick. Which article Shonkwiler and Vela-Vick derive an integral formula for two submanifolds of a visible hypersurfaces of Euclidean space. Trying to adapt the idea of them, we were behind a full formula for the hyperbolic case, following the same script, but using the geometric structure of the hyperbolic space. Moreover, it is noteworthy that the Shonkwiler article and Vela-Vick is quite succinct, leaving several arguments and unexplained passages, which also led us to go back to explain in more detail all the arguments of them and thus a " concept new " and very important had to be made, such a concept we call "conical variety," which is not a deferenciável variety of apparel and so we had to develop a little degree theory for such sets. Finally, we gave work to express " application of hyperbolic Gauss ", in order that it desempenhasse the same role that the application of Euclidean Gauss played in article Shonkwiler and Vela-Vick. / Esta dissertação teve como objetivo encontrar uma fórmula integral que calcula o linking number entre duas subvariedades de uma hipersuperfície visível do espaço hiperbólico, que será definida no texto. A motivação para isso foi o artigo "HIGHER-DIMENSIONAL LINKING INTEGRALS", cujos autores são Clayton Shonkwiler e David Shea Vela-Vick. Em tal artigo Shonkwiler e Vela-Vick derivam uma fórmula integral para duas subvariedades de uma hipersuperfície visível do espaço euclidiano. Tentando adaptar a ideia deles, fomos atrás de uma fírmula integral para o caso hiperbólico, seguindo o mesmo roteiro, porém utilizando a estrutura geométrica do espaço hiperbolico. Além disso, vale ressaltar que o artigo de Shonkwiler e Vela-Vick é bastante suscinto, deixando vários argumentos e passagens inexplicados, o que também nos levou a ir atrás de explicar com maiores detalhes toda a argumentação deles e assim, um conceito \novo"e bastante importante teve que ser apresentado, tal conceito denominamos "variedade cônica", que não é uma variedade deferenciável de fato e por isso tivemos de desenvolver um pouco a teoria do grau para tais conjuntos. Por fim, nos demos a trabalho de expressar a "aplicação de Gauss hiperbólica", com a finalidade de que ela desempenhasse o mesmo papel que a aplicação de Gauss euclidiana desempenhou no artigo de Shonkwiler e Vela-Vick.
2

The Point-Split Method and the Linking Number of Space Curves

Forsberg, Timmy January 2014 (has links)
This is a report on research done in the field of mathematical physics. It is an investigation of the concept of the linking number between two simple and closed spatial curves. The linking number is a topological invariant with scientific applications ranging from DNA biology to Topological Quantum Field Theory. Our aim is to study C ̆alug ̆areanu’s theorem, also called White’s formula, which relates the linking number to the concepts of twist and writhe. We are interested in the limit of the two curves as they approach each other. To regulate this, we introduce a regularization method that utilizes a point-split. Further we explore if the result is dependent on how the regularization is introduced. Therefor we inflict an asymmetry in the regularization, with a parameter a in the point-split intervals, to check whether the result becomes dependent on a or not. We find that the result is independent of the parameter a.
3

Étude des transitions de phases dans le modèle de Higgs abélien en (2+1) dimensions et l'effet du terme de Chern-Simons

Nebia-Rahal, Faïza 10 1900 (has links)
Nous avons investigué, via les simulations de Monte Carlo, les propriétés non-perturbatives du modèle de Higgs abélien en 2+1 dimensions sans et avec le terme de Chern-Simons dans la phase de symétrie brisée, en termes de ses excitations topologiques: vortex et anti-vortex. Le but du présent travail est de rechercher les phases possibles du système dans ce secteur et d'étudier l'effet du terme de Chern-Simons sur le potentiel de confinement induit par les charges externes trouvé par Samuel. Nous avons formulé une description sur réseau du modèle effectif en utilisant une tesselation tétraédrique de l'espace tridimensionnel Euclidien pour générer des boucles de vortex fermées. En présence du terme de Chern-Simons, dans une configuration donnée, nous avons formulé et calculé le nombre d'enlacement entre les différentes boucles de vortex fermées. Nous avons analysé les propriétés du vide et calculé les valeurs moyennes de la boucle de Wilson, de la boucle de Polyakov à différentes températures et de la boucle de 't Hooft en présence du terme de Chern-Simons. En absence du terme de Chern-Simons, en variant la masse des boucles de vortex, nous avons trouvé deux phases distinctes dans le secteur de la symétrie brisée, la phase de Higgs habituelle et une autre phase caractérisée par l'apparition de boucles infinies. D'autre part, nous avons trouvé que la force entre les charges externes est écrantée correpondant à la loi périmètre pour la boucle de Wilson impliquant qu'il n'y a pas de confinement. Cependant, après la transition, nous avons trouvé qu'il existe toujours une portion de charges externes écrantée, mais qu'après une charge critique, l'énergie libre diverge. En présence du terme de Chern-Simons, et dans la limite de constante de couplage faible de Chern-Simons nous avons trouvé que les comportements de la boucle de Wilson et de la boucle de 't Hooft ne changent pas correspondants à une loi périmètre, impliquant qu'il n'y a pas de confinement. De plus, le terme de Chern-Simons ne contribue pas à la boucle de Wilson. / We investigate, via Monte Carlo simulations, non-perturbative properties of a 2+1 dimensional Abelian Higgs model without and with the Chern-Simons term in the symmetry broken phase in terms of its topological excitations: vortices and anti-vortices. The aim of the present work is to understand what phases exist for the system in that sector and the effect of the Chern-Simons term on the confining potential induced between external charges found by Samuel. We formulate a lattice description of the effective model starting from a tetrahedral tessellation of Euclidean three space to generate non-intersecting closed vortex loops. In the presence of the Chern-Simons term, for a given configuration, we formulate and compute the linking number between different closed vortex loops. We analyse properties of the vacuum and compute the expectation value of Wilson loop operator, Polyakov loop operator at different temperatures and the 't Hooft loop operator in the presence of the Chern-Simons term. In the absence of a Chern-Simons term, as we vary the mass of the vortex loops, we find two distinct phases in the symmetry broken sector, the usual Higgs phase and a novel phase which is heralded by the appearance of the so-called infinite loops. On the other hand, we find that the force between all external charges is screened, corresponding to a perimeter law for the Wilson loop implying no confinement. However, after the transition, we find that small external charges are still screened, but after a critical value of the external charge, free energy diverges. In the presence of Chern-Simons term, and in the limit where the coupling constant is low for Chern-Simons we find that the behavior of Wilson loop does not change: it is still a perimeter law, implying no confinement. Moreover, the Chern-Simons term does not contribute to the Wilson loop. 'tHooft loop behaves like a perimeter law too.
4

Étude des transitions de phases dans le modèle de Higgs abélien en (2+1) dimensions et l'effet du terme de Chern-Simons

Nebia-Rahal, Faïza 10 1900 (has links)
No description available.

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