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Johnston, Olivia Ruth. "Distribution and biology of the marine invasive bivalve Theora lubrica (Semelidae)." Thesis, University of Canterbury. School of Biological Sciences, 2005. http://hdl.handle.net/10092/2453.
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This study examined aspects of the biology and distribution of the marine invasive bivalve Theora lubrica in the Lyttelton Basin from two distinct sampling areas. Samples were collected monthly, over a 13 month period (January 2004 and January 2005), with particular emphasis on seasonal sedimentary characteristics and contamination. The sample sites consisted of five Port sites and five Harbour sites. They were sampled using a 20 litre anchor dredge. In winter and summer, core samples from each of the sample sites were collected, and the top 1.5cm of sediment was used to obtain sediment characteristics. Sediment characteristics indicated a depositional setting, with an average grain size (diameter) of 8-10 μm, which did not vary seasonally. Analysis indicated that the sediments naturally flocculated, to the 100μm size range and were platykurtic. Organic content (OC) in the sediment in Lyttelton Port showed significant seasonal variation. OC was highest during the winter period corresponding to an increase of T. lubrica abundance. There were noticeable seasonal changes in the abundance of T. lubrica, with high winter and low summer population densities. The period for recruitment coincided with high T. lubrica densities, and the greater frequency of juveniles with shell length below 4.33 mm. Histological sections showed that spawning occurred during the summer, confirmed by the presence of high percentages of ovigerous females and mature males. Community analyses distinguished four distinct seasonal and spatial benthic populations. The populations exhibited greater total species richness during the summer (compared to the winter). T. lubrica, maintained high abundance during periods of low total species richness. Furthermore, there was evidence of a predator prey relationship between the crab Macrophthalmus hirtipes and T. lubrica. Trace metals and hydrocarbons showed seasonal and spatial variation between the Port and Harbour sediments. Only the arsenic, nickel and copper in the Port location were at concentrations likely to be toxic to the biota. No trace metals exceeded threshold limits in the Harbour. Levels of arsenic and nickel were highest in the summer and copper was at its highest concentration in the winter. However, there was little evidence to suggest that the sediment contamination affects T. lubrica or the rest of the benthic community directly. Thus, the significantly lower species richness at the Port location may be due to other influences (i.e. sediment disturbance from shipping). In conclusion T lubrica is regarded as an opportunistic marine invasive species which can inhabit areas not occupied by other marine macro-biota. T lubrica did not appear to negatively impact the other benthic species at the Lyttelton Port or Harbour sites. It provided a plentiful food source and increased species diversity in sediments that are frequently disturbed (by shipping and wave action). Furthermore, T lubrica may help reestablish native species to the Port area by filtering and processing contaminated sediments (bioturbation), potentially pioneering the way for greater species diversity in Lyttelton Port and Harbour.
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Cetlová, Tereza. "Rozhodování spotřebitele v podmínkách rizika." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-232778.
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The aim of the thesis is to afford a complex perspective of a parallel development of psychology and economics to the readers. It is suggested, how psychological experiments could be used for the overall enrichment of the classical theory of economics. In the thesis, readers are introduced to the development of economic theories over time, and also to what role a human takes as a personality. Including the thesis is the part engaging in consumer decision process.
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Tesař, Pavel. "Vysílání multimediálního obsahu s využití kompresních technik." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218002.
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The topic of the master's thesis is about transmission of multimedia via network with help of compression’s algorithm used in codec MPEG-4 part 10 and Real Time Protocol (RTP). First part of this master thesis will be familiarization with basic terms about multimedia. It will be queried about techniques of compression axioms for audio and video, justification for necessary use of compression in transmitting multimedia via network. Also, here will be subscribed principles and properties of Real Time Protocol, which was designed for multimedia stream. From the start, competent codec for implementation of two applications (client, server) with read raw video and audio data, will choose the following : compression with help of codec Theora (Vorbis), transfer via network in RTP packets, decode and play at visual form for end user. Complete subscription of implementation for both applications written in programming languages C/C++ and Java, will be certain. The basic overview about this problematic experience with implementation, which were here concluded, are the reasons for reading this master thesis.
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Křenek, Tomáš. "Audio a video vysílání s využitím real-time protokolu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218188.
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This diploma thesis focus on transmiting multimedia over computer network. There are detailed informations about protocols RTP and RTPC in a first part because a transmition over a network is realized by using these protocols. Some basic multimedia terms, FFmpeg codecs and SDL library are described in next chapters. A multimedia player using FFmpeg and SDL is implemented in a second part of thesis. The player is console application and it has basic user interface. The player reproduces video and audio from a given file. RTP communication is described in next chapters of the second part. RTP server and client are implemented there too. They are console aplications and they use data coded by Theora or Vorbis. There are summarized results in a conclusion.
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Miller, Shannon J. "Two Approaches to Clifford's Theorem." Youngstown State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1619792031825711.
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Desnoux, Pierre-Jean. "Congruences dyadiques entre nombres de classes de corps quadratiques." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37604500q.
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Movahhedi, Abbas. "Sur les p-extensions des corps p-rationnels." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37616809b.
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Polzin, Marc. "Prolongement de la valeur absolue de Gauss et problème de Skolem." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10539.
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Dans cette these, nous nous interessons au probleme suivant : soit k un corps value ultrametrique, non necessairement complet, l un corps de fonctions d'une variable sur k, w un ensemble fini de valeurs absolues sur l qui prolongent celle de k et telles que le corps residuel de l soit un corps de fonctions d'une variable sur le corps residuel de k. Existe-t-il t dans l, transcendant sur k, tel que w soit exactement l'ensemble des prolongements a l de la valeur absolue de gauss sur k(t) associee a t. Nous donnons, dans la partie 2, une condition equivalente en termes geometriques en utilisant la reduction analytique des courbes algebriques en geometrie analytique rigide (theoreme 1). Dans la partie 2, nous montrons (theoreme 2) comment ce probleme est relie a un probleme arithmetique etudie par skolem et nous definissons la "propriete de skolem locale". Enfin, dans la partie 3, nous donnons un contre-exemple, pour tout g, d'une courbe hyperelliptique de genre g qui ne satisfait pas la propriete de skolem locale
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Landreau, Bernard. "Majorations de fonctions arithmétiques en moyenne sur des ensembles de faible densité." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10629.
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Le but de cette these est d'etablir des majorations de valeurs de fonctions arithmetiques f, en moyenne sur des ensembles d'entiers a de faible densite exponentielle. En suivant des idees d'erdoes et nicolas, on commence par traiter le cas ou les ensembles a n'ont aucune structure particuliere. Il est alors possible de majorer la valeur moyenne de f sur a par une puissance du maximum de f sur a, avec un exposant inferieur a 1, d'autant plus proche de zero que l'ensemble a est riche. La partie principale du travail consiste a obtenir des majorations de la valeur f(n) par une somme de valeurs f(d) etendue aux petits diviseurs d de n et a en deduire des majorations de f en moyenne sur des ensembles a bien repartis dans les progressions arithmetiques de petite raison (par exemple, les suites polynomiales en une ou plusieurs variables). On determine en outre les fonctions f optimales. Ces methodes conduisent notamment a une nouvelle demonstration simple et particulierement rapide d'un resultat classique de van der corput
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Louboutin, Stéphane. "Arithmetique des corps quadratiques reels et fractions continues." Paris 7, 1987. http://www.theses.fr/1987PA077077.
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En appliquant la theorie des fractions continues a l'etude de l'arithmetique des corps quadratiques reels, nous pouvons repondre aux questions suivantes: 1) nous donnons deux criteres de principalite des corps quadratiques reels, le premier ne faisant intervenir que le caractere du corps et des invariants lies aux developpements en fractions continues, le second etant un equivalent reel du theoreme de frobenius-rabinovitch (qui caracterisait les corps quadratiques imaginaires principaux) et faisant intervenir ces memes invariants. 2) nous determinons (explicitement sous l'hypothese de riemann) tous les corps quadratiques reels de calibre 1, 2, 3 ou 5. 3) nous donnons des criteres de trivialite du groupe des classes pour les corps de richaud-degert, ou nous appelons trivial un groupe des classes reduit a son sous-groupe des classes ambiges (i. E. Des classes de carre la classe principale). Ces criteres sont du meme type que ceux donnes au 1). 4) pour cette meme famille de corps nous donnons des minorations du nombre de classes d'ideaux lorsque nos criteres nous assurent que ces corps ne sont pas principaux. 5) nous donnons deux familles de corps quadratiques reels pour lesquelles nous pouvons specifier un peu plus les criteres du 1). Ces familles sont obtenues en recherchant les d congrus a 1 modulo 4 tels que l'entier du corps egal a (1+racine carree de d)/2 admette un developpement en fractions continues d'une des deux formes suivante: (g,a,a,i<-,a,2g-1) ou (g,a,b,a,b,i<-, a,b,i<-,a,b,a,2g-1). Par des etudes numeriques nous montrons qu'il est raisonnable de penser que ces deux familles contiennent une infinite de corps non trivialement non principaux, c'est-a-dire non principaux mais de 2-rang du groupe des classes egal a 0. Finalement, sous l'hypothese de riemann nous donnons les corps principaux de ces deux familles: ils sont en nombre fini
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Emsalem, Michel. "I : Deux problèmes d'analyse réelle et p-adique. II: Autour de la conjecture de Leopoldt : Un point de vue transcendant." Paris 6, 1987. http://www.theses.fr/1987PA066069.
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Le present recueil de travaux comporte deux parties. La premiere traite deux problemes d'analyse reelle et p-adique. L'un concerne les fonctions moyenne periodiques et les fonctions presque periodiques dont le spectre possede une certaine propriete arithmetique, l'autre porte sur l'approximation ponderee de fonctions sur un corps de nombres p-adiques. La seconde partie a pour theme l'application de theoremes de transcendance a des situations de theorie des nombres. Les ingredients transcendants sont d'un cote le theoreme de baker-brumer sur l'independance lineaire sur q de logarithmes p-adiques de nombres algebriques, de l'autre un theoreme de m. Waldschmidt dont un avatar dans le cas du groupe multiplicatif donne une minoration du rang de matrices dont les coefficients sont des logarithmes de nombres algebriques. Une amelioration de ce dernier theoreme est donnee qui permet de montrer qu'a des exceptions pres, il n'y a dans une z::(p)-extension donnee d'un corps de nombres qu'un nombre fini de places qui se decomposent totalement. Le theoreme de baker-brumer, quant a lui, classiquement utilise a la demonstration de la conjecture de leopoldt dans le cas d'une extension abelienne de q ou d'un corps quadratique imaginaire, est utilise ici pour donner des minorations du rang p-adique des unites d'un corps de nombres et pour fournir des exemples non triviaux ou la conjecture de leopoldt est verifiee pour tout nombre premier p
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Langevin, Michel. "Methodes transcendantes en theorie des nombres." Paris 6, 1987. http://www.theses.fr/1987PA066178.
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Par une utilisation conjointe de techniques de transcendance ou elementaires, on minore soit le plus grand facteur premier, soit la partie sans facteur carre, soit encore le nombre de diviseurs premiers de produits d'entiers en progression arithmetique ou de termes de meme nature. On aborde egalement par ces procedes le probleme d'erdoes-woods, la conjecture de grimm. . . Dans une seconde partie, on emploie le schema des demonstrations de transcendance pour etudier des problemes de theorie des nombres ou d'analyse lies a la repartition des zeros des polynomes : probleme de lehmer, probleme de favard, extensions du theoreme de bernstein. . .
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Balazard, Michel. "Sur la repartition des valeurs de certaines fonctions arithmetiques additives." Limoges, 1987. http://www.theses.fr/1987LIMO0014.
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Ce travail concerne la distribution des valeurs de fonctions arithmétiques comptant, de diverses facons, le nombre de facteurs premiers d'un entier. Lorsqu'on se restreint aux facteurs premiers appartenant a un ensemble E, on obtient un encadrement uniforme des lois locales. Cet encadrement est remplacé par une formule asymptotique si E est l'ensemble de tous les nombres premiers ou si l'on limite a un certain domaine le parametre des lois locales. On aborde aussi l'étude de la distribution conjointe de deux fonctions additives, obtenant ainsi des formules a terme principal discontinu pour les grandes deviations de la moyenne des exposants dans la décomposition en facteurs premiers et du nombre de diviseurs d'un entier.
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Azzouza, Nour-Eddine. "Majorations effectives du nombre d'entiers inferieurs a x, et ayant exactement k facteurs premiers." Limoges, 1988. http://www.theses.fr/1988LIMO0032.
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Soit n(x,k), le cardinal de l'ensemble des entiers inferieurs a x, et ayant une quantite fixee k, de facteurs premiers. On etudie le comportement de cette quantite pour en obtenir une formule asymptotique uniforme pour k dans un intervalle donne. Il est interessant d'etablir des majorations effectives de n(x,k) valable pour tout k entier. Le resultat depend de majorations explicites de sommes de fonctions arithmetiques
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Garotta, Odile. "Suites presque scindées d'algèbres intérieures et algèbres intérieures des suites presque scindées." Paris 7, 1988. http://www.theses.fr/1988PA077184.
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Dans le cadre de l'etude des representations modulaires d'un groupe fini sur un corps, nous generalisons la notion, introduite par auslander et reiten, de "suite exacte presque scindee" de nodules (sur l'algebre de groupe), en une notion de "systemes d'idempotents" (dits systemes de auslander-reiten) dans une algebre "interieure" (du point de vue de l'operation du groupe) symetrique quelconque. Raisonnant a l'interieur des algebres, nous donnons, comme dans la theorie classique, un resultat d'"existence et unicite" des systemes de auslander-reiten. D'autre part le point de vue de l'"algebre commutante" des systemes nous permet de decrire, par le biais des groupes pointes, la restriction des systemes de auslander-reiten au vortex de leur terme extreme, et de donner un critere pour que ce vortex coincide avec celui du systeme. En particulier on a egalite pour les suites presque scindees se terminant par un module simple
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Tapsoba, Théodore. "Complexité de suites automatiques." Aix-Marseille 2, 1987. http://www.theses.fr/1987AIX22069.
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On montre que dans une suite u minimale obtenue par substitution injective uniforme, tout mot lu dans u et de longueur assez longue admet une factorisation unique. Ce resultat permet de reconnaitre par un automate l'application qui a n associe p de n plus un, moins p de n, ou p de n designe le nombre de mots lus dans u, de longueur n
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Bouda, Ahmed. "Localisation de la symétrie BRST en théorie des cordes." Bordeaux 1, 1989. http://www.theses.fr/1989BOR10531.
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La symetrie brst locale pour une classe generale d'actions fixees de jauge de la corde bosonique est utilsiee pour etudier les anomalies possibles de l'algebre des courants brst correspondants. Une analyse analogue est faite pour la theorie conforme obtenue en introduisant les differentielles de beltrami. Une nouvelle algebre brst locale pour le groupe de weyl x lorentz x lorentz x diffeomorphisme est construite dans un espace a n-dimensions. Elle est appliquee pour n=2 a la corde bosonique et pour n=4 a la gravite d'einstein
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Thera, Aissata Traore. "Bacterial wilt management a prerequisite for a potato seed certification program in Mali /." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/thera/TheraA1207.pdf.
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Gomaa, Walid. "Model theory and complexity theory." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7227.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Computer Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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at, Gerald Teschl@univie ac. "On the Number of Eigenvalues of Jacobi Operators." ESI preprints, 2001. ftp://ftp.esi.ac.at/pub/Preprints/esi1079.ps.
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Smith, Stephen D. "Theory against itself : literary theory and the limits of theory." Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334294.
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Frøyshov, Kim A. "On Floer homology and four-manifolds with boundary." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282194.
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Petschulat, Cap. "Transparency in formal proof." [Boise, Idaho] : Boise State University, 2009. http://scholarworks.boisestate.edu/td/54/.
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Egan, Sarah. "Nash equilibria in games and simplicial complexes." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500758.
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Nash's Theorem is a famous and widely used result in non-cooperative game theory which can be applied to games where each player's mixed strategy payoff function is defined as an expectation. Current proofs of this Theorem neither justify why this constraint is necessary or satisfactorily identifies its origins. In this Thesis we change this and prove Nash's Theorem for abstract games where, in particular, the payoff functions can be replaced by total orders. The result of this is a combinatoric proof of Nash's Theorem. We also construct a generalised simplicial complex model and demonstrate a more general form of Nash's Theorem holds in this setting. This leads to the realisation Nash's Theorem is not a consequence of a fixed-point theorem but rather a combinatoric phenomenon existing in a much more general mathematical model.
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Ali, T. "String theory and conformal field theory." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595446.
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In this thesis we consider some aspects of two dimensional Conformal Field Theory and their connection to String Theory. We have also studied some aspects of supersymmetry of M-Theory on Ricci-flat seven manifolds with 4-form fluxes. We concentrate mainly on certain supersymmetric extensions of the coset models due to Goddard, Kent and Olive (GKO). These models are known as the Kazama-Suzuki (KS) models and they are characterized by their N = 2 superconformal symmetry. Two series of the KS models enjoy a duality called level-rank duality which can be described roughly as duality between the dimension of the target space and the level of coset. We believe that the path-integral approach is the closest in spirit to string theory. Therefore, we formulate the level-rank duality of KS models in the path-integral approach by using the realization of GKO cosets as gauged Wess-Zumino-Novikov-Witten (gauged-WZNW) models. We derive, for a class of KS models, an expression for the partition function which is symmetric in the parameters of the level-rank duality. We compute the central charge of the models from this expression which matches that of Kazama and Suzuki in the operator approach. We then work out the target space metric and the dilation of the gauged-WZNW model based on the GKO coset SU(3)/(SU(2) x U(1)). It turns out to be quite a complicated metric with a non-trivial dilation. We verify, as a consistency check, that they satisfy the appropriate string theory effective equations of motion. We then argue that this background can arise naturally in type II string theory compactified down to AdS3 space. We then turn to Eleven Dimensional Supergravity which is the low energy limit of M-theory. We adopt a metric ansatz which is a warped product of four dimensional Minkowski space and a (non-compact) seven manifold with 4-form fluxes turned on it. We derive the condition for unbroken supersymmetry with fluxes and non-trivial warp-factor. We show that the same condition implies that the seven manifold is conformal to a Ricci-flat manifold. We also point out the limitation of some naive ansatze about the structure of the Killing spinor. At this stage we are unable to give an explicit solution to the supersymmetry condition.
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Levikov, Filipp. "L-theory, K-theory and involutions." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=201918.
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In Part 1, we consider two descriptions of L-homology of a (polyhedron of a) simplicial complex X. The classical approach of Ranicki via (Z,X)-modules (cf. [Ran92]) iswell established and is used in Ranicki’s definition of the total surgery obstruction and his formulation of the algebraic surgery exact sequence (cf. [Ran79], [Ran92],[KMM]). This connection between algebraic surgery and geometric surgery has numerous applications in the theory of (highdimensional) manifolds. The approach described in [RW10] uses a category of homotopy complexes of cosheaves to construct for a manifold M a (rational) orientation class [M]L• in symmetric L-homology which is topologically invariant per construction. This is used to reprove the topological invariance of rational Pontryagin classes. The L-theory of the category of homotopy complexes of sheaves over an ENR X can be naturally identified with L-homology of X. If X is a simplicial complex, both definitions give L-homology, there is no direct comparison however. We close this gap by constructing a functor from the category of (Z,X)-modules to the category of homotopy cosheaves of chain complexes of Ranicki-Weiss inducing an equivalence on L-theory. The work undertaken in Part 1 may be considered as an addendum to [RW10] and suggests some translation of ideas of [Ran92] into the language of [RW10]. Without significant alterations, this work may be generalised to the case of X being a △-set. The L-theory of △-sets is considered in [RW12]. Let A be a unital ring and I a category with objects given by natural numbers and two kinds of morphisms mn → n satisfying certain relations (see Ch.3.4). There is an I-diagram, given by n 7→ ˜K (A[x]/xn) where the tilde indicates the homotopy fiber of the projection induced map on algebraic K-theory (of free modules) K(A[x]/xn) → K(A). In Part 2 we consider the following result by Betley and Schlichtkrull [BS05]. After completion there is an equivalence of spectra TC(A)∧ ≃ holim I ˜K(A[x]/xn)∧ where TC(A) is the topological cyclic homology of A. This is a very important invariant of K-theory (cf. [BHM93], [DGM12]) and comes with the cyclotomic trace map tr : K(A) → TC(A). In [BS05], the authors prove that under the above identification the trace map corresponds to a “multiplication” with an element u∞ ∈ holim I ˜K (Z[x]/xn). In this work we are interested in a generalisation of this result. We construct an element u∞ ∈ holim I ˜K(Cn). where Cn can be viewed as the category of freemodules over the nilpotent extension S[x]/xn of the sphere spectrum S. Let G be a discrete group and S[G] its spherical group ring. Using our lift of u∞ we construct a map trBS : K(S[G]) → holim I ˜K (CG n ) where CG n should be interpreted as the category of free modules over the extension S[G][x]/xn. After linearisation this map coincides with the trace map constructed by Betley and Schlichtkrull. We conjecture but do not prove, that after completion the domain coincides with the topological cyclic homology of S[G]. Some indication is given at the end of the final chapter. To construct the element u∞ we rely on a generalisation of a result of Grayson on the K-theory of endomorphisms (cf. [Gra77]). Denote by EndC the category of endomorphisms of finite CW-spectra and by RC the Waldhausen category of free CW-spectra with an action of N, which are finite in the equivariant sense. Cofibrations are given by cellular inclusions and weak equivalences are given bymaps inducing an equivalence of (reduced) cellular chain complexes of Z[x]-modules, after inverting the set {1 + xZ[x]}. In Chapter 5 we prove (5.8) that there is a homotopy equivalence of spectra ˜K (EndC) ≃ ˜K (RC). where tildes indicate that homotopy fibres of the respective projections are considered. Furthermore, we pursue the goal of constructing an involutive tracemap for themodel of [BS05]. We employ the framework ofWaldhausen categories with duality (cf. [WW98]) to introduce for any G involutions on holim I ˜K (CG n ). We give enough indication for our trace map being involutive, in particular in the last three sections of Chapter 5, we sketch how the generalisation of the theoremof Grayson (5.8) can be improved to an involutive version. In the final chapter, we develop this further. Assuming that the element u∞ ∈ holim I ˜K (Cn) is a homotopy fixed point of the introduced involution, we construct a map from quadratic L-theory of S[G] to the Tate homology spectrum of Z/2 acting on the fibre of trBS (see 6.9) : L•(S[G]) → (hofib(trBS))thZ/2 and discuss the connection of this to a conjecture of Rognes andWeiss. The two parts of the thesis are preluded with their own introduction andmay be read independently. The fewcross references are completely neglectible.
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Palmer, Sam. "Higher gauge theory and M-theory." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/3054.
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In this thesis, the emerging field of higher gauge theory will be discussed, particularly in relation to problems arising in M-theory, such as selfdual strings and the so-called (2,0) theory. This thesis will begin with a Nahm-like construction for selfdual strings using loop space, the space of loops on spacetime. This construction maps solutions of the Basu-Harvey equation, the BPS equation arising in the description of multiple M2-branes, to solutions of a selfdual string equation on loop space. Furthermore, all ingredients of the construction reduce to those of the ordinary Nahm construction when compactified on a circle with all loops restricted to those wrapping the circle. The rest of this thesis, however, will not involve loop space. We will see a Nahm-like construction for the case of infinitely many selfdual strings, suspended between two M5-branes. This is possible since the limit taken renders the fields describing the M5-branes abelian. This avoids the problem which the rest of this thesis focuses on: What fields describe multiple M5-branes? The answer is likely to involve higher gauge theory, a categorification of gauge theory which describes the parallel transport of extended objects. Any theories which involves 3-algebras, including current M2-brane models and the Lambert-Papageorgakis M5-brane model, are examples of higher gauge theories. Recently, a class of models with N = (1, 0) supersymmetry have been found, with significant overlap with algebraic structures in higher gauge theory. This overlap suggests that the full N = (2, 0) theory could involve semistrict L∞-algebras. Finally, we will see some explicit selfdual string solutions, which may fit into these frameworks.
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Shi, Ronggang. "Equidistribution of expanding measures with local maximal dimension and Diophantine Approximation." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1242259439.
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Walters, Mark Jon. "Ramsey theory, discrepancy theory and related areas." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621647.
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Stefański, Bogdan. "String theory, dirichlet branes and K-theory." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621023.
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Sacco, Damiano. "Aspects of F-Theory and M-Theory." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/aspects-of-ftheory-and-mtheory(b5d27efa-8fc4-47a4-b259-a7b8dd9c218f).html.
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Non-perturbative phenomena have received much attention in string theory in the last years. M-Theory and F-Theory are the two main frameworks in which it is possible to explore such phenomena. This thesis focuses on aspects of both theories. In the first part of this thesis we study F-Theory compactifications with additional abelian gauge symmetries. This was motivated by problems affecting usual F-Theory compactifications and 4-dimensional Grand Uni ed Theories such as the presence of proton decay operators, which could in principle be resolved with additional abelian symmetries. In the F-Theory context, this translated into the novel analysis of elliptic brations with additional (two, in particular) rational sections. A systematic study of the possible degenerations of such elliptic brations through the application of Tate's algorithm was carried out and provided new insight into the phenomenology of F-Theory models with additional U(1) factors. The second part of this thesis consists of the study of some aspects of membranes in M-Theory. D-branes in string theory are well understood thanks to a perturbative definition via open strings. On the contrary, membranes and vebranes in M-Theory lack such a description and their effective theories are not as well understood. In particular the theory on parallel M5-branes, the so-called (2,0) theory, was studied in some detail. Following a number of results and dualities in lower dimensional field theories obtained in the last years starting from the (2,0) theory, the latter was compactified on a 2-dimensional sphere to obtain a 4-dimensional sigma model into the moduli space of monopoles. A supergravity background was turned on in order to preserve supersymmetry and an intermediate reduction to 5-dimensional N = 2 Super-Yang-Mills theory was used by considering the two-sphere as a circle bration over an interval. Insight into the theory on parallel M5-branes was also gained by relating it to the better known dynamics on coincident M2-branes. This followed a recent proposal for the realization of the (2,0) algebra on a non-abelian tensor multiplet through the use of 3-algebras. In this thesis we generalize this proposal and nd an algebraic structure which describes two parallel M5-branes or two parallel M2-branes depending on whether a particular abelian three-form is turned on.
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Winterhalter, Théo. "Formalisation and Meta-Theory of Type Theory." Thesis, Nantes, 2020. http://www.theses.fr/2020NANT4012.
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Dans cette thèse, je parle de la méta-théorie de la théorie des types et de la façon de la formaliser dans un assistant de preuve. Je me concentre d’abord sur une traduction conservative de la théorie des types extensionnelle vers la théorie des types intensionnelle ou faible, entièrement écrite en Coq. La première traduction consiste en une suppression de la règle de reflection de l’égalité, tandis que la deuxième traduction produit quelque chose de plus fort : la théorie des types faibles est une théorie des types sans notion de conversion. Le résultat de conservativité implique que la conversion n’augmente pas la puissance logique de la théorie des types. Ensuite, je montre ma contribution au projet MetaCoq de formalisation et de spécification de Coq au sein de Coq. En particulier, j’ai travaillé sur l’implantation d’un vérificateur de type pour Coq, en Coq. Ce vérificateur de type est prouvé correct vis à vis de la spécification et peut être extrait en code OCaml et exécuté indépendamment du vérificateur de type du noyau de Coq. Pour que cela fonctionne, nous devons nous appuyer sur la métathéorie de Coq que nous développons, en partie, dans le projet MetaCoq. Cependant, en raison des théorèmes d’incomplétude de Gödel, nous ne pouvons pas prouver la cohérence de Coq dans Coq, ce qui signifie que certaines propriétés — principalement la forte normalisation — doivent être supposées, c’est-à-dire prises comme axiomesIn this thesis, I talk about the metatheory of type theory and about how to formalise it in a proof assistant. I first focus on a conservative translation between extensional type theory and either intensional or weak type theory, entierely written in Coq. The first translation consists in a removal of the reflection of equality rule, whereas the second translation produces something stronger: weak type theory is a type theory with no notion of conversion. The conservativity result implies that conversion doesn’t increase the logical power of type theories. Then, I show my work for the Meta- Coq project of formalising and specifying Coq within Coq. In particular I worked on writing a type-checker for Coq, in Coq. This type checker is proven sound with respect to the specification and can be extracted to OCaml code and run independently of Coq’s kernel type-checker. For this to work we have to rely on the meta-theory of Coq which we develop, in part, in the MetaCoq project. However, because of Gödel’s incompleteness theorems, we cannot prove consistency of Coq within Coq, and this means that some properties— mainly strong normalisation—have to be assumed, i.e. taken as axioms
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Berg, Deborah. "Connections Between Voting Theory and Graph Theory." Scholarship @ Claremont, 2005. https://scholarship.claremont.edu/hmc_theses/178.
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Mathematical concepts have aided the progression of many different fields of study. Math is not only helpful in science and engineering, but also in the humanities and social sciences. Therefore, it seemed quite natural to apply my preliminary work with set intersections to voting theory, and that application has helped to focus my thesis. Rather than studying set intersections in general, I am attempting to study set intersections and what they mean in a voting situation. This can lead to better ways to model preferences and to predict which campaign platforms will be most popular. Because I feel that allowing people to only vote for one candidate results in a loss of too much information, I consider approval voting, where people can vote for as many platforms as they like.
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Leclerc, Philip. "Prospect Theory Preferences in Noncooperative Game Theory." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3522.
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The present work seeks to incorporate a popular descriptive, empirically grounded model of human preference under risk, prospect theory, into the equilibrium theory of noncooperative games. Three primary, candidate definitions are systematically identified on the basis of classical characterizations of Nash Equilibrium; in addition, three equilibrium subtypes are defined for each primary definition, in order to enable modeling of players' reference points as exogenous and fixed, slowly and myopically adaptive, highly flexible and non-myopically adaptive. Each primary equilibrium concept was analyzed both theoretically and empirically; for the theoretical analyses, prospect theory, game theory, and computational complexity theory were all summoned to analysis. In chapter 1, the reader is provided with background on each of these theoretical underpinnings of the current work, the scope of the project is described, and its conclusions briefly summarized. In chapters 2 and 3, each of the three equilibrium concepts is analyzed theoretically, with emphasis placed on issues of classical interest (e.g. existence, dominance, rationalizability) and computational complexity (i.e, assessing how difficult each concept is to apply in algorithmic practice, with particular focus on comparison to classical Nash Equilibrium). This theoretical analysis leads us to discard the first of our three equilibrium concepts as unacceptable. In chapter 4, our remaining two equilibrium concepts are compared empirically, using average-level data originally aggregated from a number of studies by Camerer and Selten and Chmura; the results suggest that PT preferences may improve on the descriptive validity of NE, and pose some interesting questions about the nature of the PT weighting function (2003, Ch. 3). Chapter 5 concludes, systematically summarizes theoretical and empirical differences and similarities between the three equilibrium concepts, and offers some thoughts on future work.
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Kessel, Pan. "The physics of higher-spin theories." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17700.
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Höhere Spin Theorien haben in den letzten Jahren große Aufmerksamkeit gefunden. Ein Grund dafür ist, dass diese Theorien dual zu besonders einfachen konformen Feldtheorien sind. Die einzigen bekannten wechselwirkenden höheren Spin Theorien wurden von Vasiliev in einem sehr ungewöhnlichen Formalismus und mit unendlich vielen Hilfsfeldern konstruiert. Die vorliegende Arbeit extrahiert die Physik, die durch diese Gleichungen beschrieben wird. Wir untersuchen im Detail die Wechselwirkungen, das Spektrum sowie die Lokalitätseigenschaften der Vasiliev Theorie. Diese Arbeit ist die erste systematische Untersuchung der Vasiliev Theorie auf wechselwirkender Ebene (nur ausgedrückt durch physikalische Felder).Higher-spin theories have received significant attention over the last years. This is because they arise as the bulk duals of comparatively tractable conformal field theories. The only known interacting higher-spin theories were constructed by Vasiliev and are formulated in a highly non-standard way in terms of an infinite number of auxiliary fields. This thesis extracts physics out of Vasiliev theory. We study in detail its interactions, spectrum and locality properties. We consider both the three- and four-dimensional case. Our work represents the first systematic study of Vasiliev theory at the interacting level (in terms of physical fields only).
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Saibi, Amokrane. "Outils Génériques de Modélisation et de Démonstration pour la Formalisation des Mathématiques en Théorie des Types. Application à la Théorie des Catégories." Phd thesis, Université Pierre et Marie Curie - Paris VI, 1999. http://tel.archives-ouvertes.fr/tel-00523810.
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Poernomo, Iman Hafiz 1976. "Variations on a theme of Curry and Howard : the Curry-Howard isomorphism and the proofs-as-programs paradigm adapted to imperative and structured program synthesis." Monash University, School of Computer Science and Software Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9405.
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Akdenizli, Dilek. "Critical Theory, Deliberative Democracy And International Relations Theory." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606881/index.pdf.
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In the 20th century, Critical Theory has been very influential on every discipline of social sciences including international relations. According to Critical IR Theory, traditional theories are problem solving and try to explain repetition and recurrence, rather than changehowever, the main subject matter of an IR theory should be the change itself. The idea of change is also constitutive of Habermasian political thought. Jü
rgen Habermas, as a critical theorist, has developed the model of Deliberative Democracy to provoke a change in the political life of the Western countries towards a more ethical politics. According to Habermas, such a change will eliminate the legitimacy crisis occurred in Western democracies. Therefore, Habermas aims at strengthening the moral basis of democratic understanding in order to make masses participate actively in decision making processes. According to him, rational consensus must be at the centre of democracy, and it can be reached, only if every part of the deliberation has the opportunity to express their arguments equally. Once the idea of rational consensus becomes a regulative rule of democracy, it is possible to change the nature of politics, including international politics
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Halter, Sebastian. "Inflation from field theory and string theory perspectives." Diss., Ludwig-Maximilians-Universität München, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-156269.
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Braun, Volker Friedrich. "K-theory and exceptional holonomy in string theory." Doctoral thesis, [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965401650.
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Acharya, Bobby Samir. "Joyce compactifications of string theory and M theory." Thesis, Queen Mary, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299930.
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Bedford, James Andrew Peter. "On perturbative field theory and twistor string theory." Thesis, Queen Mary, University of London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479158.
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Fritz, Jan-Stefan. "Regime theory : a new theory of international institutions." Thesis, London School of Economics and Political Science (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392682.
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Knoll, Meredith Sharyn. "Rethinking the #theory' in theory of mind development." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272550.
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Mohamed, Adam. "Local Class Field Theory via Lubin-Tate Theory /." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1936.
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Corson, Samuel M. "Applications of Descriptive Set Theory in Homotopy Theory." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2401.
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This thesis presents new theorems in homotopy theory, in particular it generalizes a theorem of Saharon Shelah. We employ a technique used by Janusz Pawlikowski to show that certain Peano continua have a least nontrivial homotopy group that is finitely presented or of cardinality continuum. We also use this technique to give some relative consistency results.
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Karch, Andreas. "Field Theory Dynamics from branes in String Theory." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 1998. http://dx.doi.org/10.18452/14371.
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Nach jahrelanger Suche hat sich bis heute Stringtheorie als einziger Kandidat einer konsistenten Quantentheorie der Gravitation herauskristallisiert. Um aus der Stringtheorie präzise Vorhersagen für unsere Niederenergiewelt zu gewinnen, ist es notwendig, das Vakuumproblem zu lösen, das heißt einen Mechanismus zu finden, der aufzeigt, in welchem Stringvakuum wir leben und warum die Natur dieses ausgewählt hat. Die Beantwortung dieser Frage benötigt nicht-perturbative Informationen.Diese wurden erst in jüngster Zeit zugänglich. Eine besondere Rolle in dieser Entwicklung spielten die sogenannten D-branes. Sie stellen mögliche nicht-perturbative Beiträge zu Stringamplituden dar. Die Identifizierung, daß D-branes einfach Objekte sind, auf denen Strings enden können, ermöglicht sie zu handhaben und zu zeigen, daß ihre Dynamik im wesentlichen durch Eichtheorien erfaßt wird. D-branes erlaubten, zahlreiche Dualit\ätssymmetrien zu etablieren, deren Haupta ussage zu sein scheint, daß alle 5 Stringtheorien sowie 11d Supergravitation nur verschiedene perturbative Limites einer fundamentalen 11d Theorie sind, T-Theorie. In dieser Arbeit habe ich mich mit einigen Anwendungen dieser Ideen beschäftigt. Die Tatsache, daß D-branes durch Super Yang-Mills Theorien beschrieben werden, erlaubt uns einen Stringhintergrund derart zu präparieren, daß wir nahezu jede Eichtheorie als relevante Niederenergiebeschreibung erhalten können. Eine besonders verbreitete Variante dieser Idee sind die sogenannten ``Hanany Witten setups'', in denen dieser Stringhintergrund nur aus flachen branes im flachen Raum besteht. Mit Hilfe dieser Technik habe ich verschiedene Dualitätssymmetrien in Feldtheorien auf Stringdualitäten zurückgeführt. Ferner ist es möglich, mit Hilfe der branes die Existenz nicht trivialer Fixpunkt Theorien in sechs Dimensionen zu beweisen und einige ihrer Eigenschaften zu analysieren. Einige dieser Fixpunkte beschreiben Phasenübergänge zwischen verschiedenen brane Hintergründen. Unter anderem läßt es sich auf diese Weise zeigen, daß es in 4 Dimensionen Übergänge zwischen chiralen und nicht chiralen Vacua gibt. Ferner wurde gezeigt, daß alle anderen Zugänge zu dem Problem, Eichtheorien in Stringtheorie einzubetten, im wesentlichen äquivalent zum HW Ansatz sind, in dem Sinn, daß die entsprechenden Stringhintergründe dual zueinander sind. Dadurch können neue Aspekte der String T-Dualität verstanden werden, so wie z.B. T-Dualitäat für brane Segmente und gebogene branes.Außerdem erlaubt uns diese Verbindung, die Phasenübergänge, die wir im HW Bild entdeckt haben, tatsächlich als Übergänge zwischen topologisch verschiedenen Stringkompaktifizierungen zu verst ehen.In this thesis I discussed several applications of the connection of non-perturbative string theory and SYM theory. In Chapter 1 I reviewed the physics of D-branes as one example of a non-perturbative effect in string theory. Their dynamics is dominated by gauge theory. This fact can be used to engineer certain string backgrounds which yield interacting SYM theories as their low-energy description. In Chapter 2 I then introduced one of the approaches in detail, the HW setup. I gave a summary of the identification of the classical gauge theory, showed how quantum effects manifest themselves in the brane picture and how to solve them. This way of embedding gauge theories into string theories has several interesting applications. These were the topic of Chapter 3. First I discussed dualities in field theory and showed how they arise as a natural consequence of string duality. As a second application I used branes to prove the existence of non-trivial fixed point theories in 6 dimensions and to study their properties. Some of these fixed points describe phase transitions between two different brane configurations. From a 4d point of view these 6d transitions can induce a chiral non-chiral transition. In Chapter 4 I discussed the relation of the HW setup with the other approaches of embedding gauge theory into string theory, especially the branes as probes approach. The different ways of embedding gauge theories in string theory are shown to be actually T-dual as string backgrounds. For one this allowed us to explore several new aspects of T-duality, like T-duality for bended branes and branes endin g on branes. In addition this relation can be used to show that the transitions found in the brane picture can as well be understood as transitions between topologically distinct compactifications of string theory. Some open problems and directions for further research were mentioned in Chapter 5.
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Lake, Matthew James. "Cosmic necklaces in string theory and field theory." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/523.
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In this thesis we investigate astrophysical phenomena which arise in models with compact extra dimensions, focussing on the cosmological consequences of strings which wrap cycles in the internal space. Embedding our strings in the Klebanov-Strassler geometry we develop a concrete model of cosmic necklaces and investigate the formation of primordial black holes and dark matter relics from necklace collapse. Using data from the EGRET cosmic ray experiment, we place bounds on the parameters which de ne the warped deformed conifold, including the value of the warp factor and the radius of the compact space. Chapter 1 provides a brief overview, while background material is included in chapter 2, and these results are presented in chapter 3. In chapter 4 we analyse the dynamics of wound strings with angular momentum in the compact dimensions and determine the equation of motion for a self-oscillating loop. Finally, in chapter 5 we suggest a eld-theoretic dual for wound-string necklaces based on a modi cation of the standard Abelian-Higgs model. After introducing spatially-dependent couplings for the scalar and vector elds, we propose a static, non-cylindrically symmetric solution of the resulting eld equations which describes a \pinched" string with neighbouring vortex and anti-vortex regions. The similarities between pinched strings and the four-dimensional appearance of wound-string states are then examined and a correspondence between eld theory and string theory parameters is suggested. We nd that the topological winding number of the eld theory vortex may be expressed in terms of parameters which de ne the winding of the dual string around the compact space. According to this relation, the topological charge is equal to unity when the string has zero windings, and the standard Nielsen-Olesen duality is recovered in this limit. One key result of this work is an estimate of the Higgs boson mass (at critical coupling) in terms of the parameters which de ne the Klebanov-Strassler geometry and which, in principle, may be constrained by cosmological observations.
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Letzter, Shoham. "Extremal graph theory with emphasis on Ramsey theory." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709415.
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Feng, Bo 1971. "D-branes, gauge theory and string field theory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8491.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.Includes bibliographical references (p. 245-262).
In this thesis, we present several works done in last three years. They include three directions in the string theory. In the first direction, we use the brane setup to find mirror pairs of SO(n) and Sp(k) gauge groups for N = 4 three-dimensional gauge field theories. To reach this result, we analyze carefully the s-configuration and predict a nontrivial string dynamics, i.e., the splitting of branes on the orientifold planes. In the second direction, we develop the "inverse algorithm" and use it to get nontrivial world volume theories of D-branes probing more exotic singularities. In this process, we find the "toric duality" which relates different phases of D-brane probe theories. We realize later that the toric duality is an example of the more powerful Seiberg-duality so these different phases are related by the Seiberg duality. In the third direction, by using numerical calculation we get a strong evidence to support the second conjecture of Sen's three conjectures. We show that if the identity field is BRST exact state around the tachyon vacuum, the open string spectrum will decouple from the physics and leave only the closed string spectrum.
by Bo Feng.
Ph.D.