In this thesis we use the holographic gauge/gravity duality to study two different aspects of strongly coupled non-Abelian plasmas. In the first topic we study the effects of strong (Abelian) magnetic fields on the transport coefficients of a strongly coupled non-Abelian plasma. Due to the spatial anisotropy created by the magnetic field, the most general viscosity tensor of a magnetized plasma has 5 shear viscosity coefficients and 2 bulk viscosities. We use the holographic correspondence for a strongly coupled N=4 Supersymmetric Yang-Mills (SYM) plasma to evaluate the shear viscosity perpendicular to the magnetic field and the shear viscosity parallel to the field. In the presence of a magnetic field, the shear viscosity perpendicular to the field saturates the Kovtun-Son-Starinets viscosity bound while in the direction parallel to the field the bound is violated. The second topic investigated in this thesis is motivated by the study of the near equilibrium behavior of strongly interacting non-Abelian plasmas that display a critical point in their phase diagram. We focus on the spectra of non-hydrodynamic quasinormal modes of a strongly coupled N=4 SYM plasma in the presence of a chemical potential, which displays a critical point in equilibrium. Except close to the critical point, we observe that by increasing the chemical potential one generally increases the damping rate of the quasinormal modes, which leads to a reduction of the characteristic equilibration times in the dual strongly coupled plasma. However, as one approaches the critical point the typical equilibration time increases though its derivative with respect to the chemical potential diverges with an exponent equal to -1/2. We also find a purely imaginary non-hydrodynamical mode in the vector diffusion channel at nonzero chemical potential which dictates the equilibration time in this channel near the critical point. / Nessa tese usamos a dualidade holográfica calibre/gravidade para estudar dois aspectos diferentes de plasmas não-Abelianos fortemente acoplados. No primeiro tópico estudamos os efeitos de campos magnéticos (Abelianos) intensos sobre o coeficientes de transporte de um plasma não-Abeliano fortemente acoplado. Devido à anisotropia espacial criada pelo campo magnético, o tensor de viscosidade mais geral de um plasma magnetizado deve possuir 5 coeficientes de viscosidade de cisalhamento e 2 de viscosidade volumétrica. Usamos a correspondência holográfica para um plasma N=4 Supersimétrico de Yang-Mills (SYM) fortemente acoplado para calcular a viscosidade de cisalhamento perpendicular ao campo magnético e a viscosidade de cisalhamento paralela ao campo. Na presença do campo magnético, a viscosidade de cisalhamento perpendicular ao campo satura o limite viscoso de Kovtun-Son-Starinets enquanto que na direção paralela ao campo o limite é violado. O segundo tópico investigado nessa tese é motivado pelo estudo do comportamento próximo ao equilíbrio de plasmas não-Abelianos fortemente interagentes que exibem um ponto crítico em seus diagramas de fase. Focamos no espectro dos modos quasinormais não-hidrodinâmicos de um plasma N=4 SYM fortemente acoplado na presença de um potencial químico, que exibe um ponto crítico no equilíbrio. Exceto próximo ao ponto crítico, observamos que ao aumentar o potencial químico geralmente se intensifica a taxa de amortecimento dos modos quasinormais, que levam à redução dos tempos de equilibração característicos do plasma dual fortemente acoplado. Entretanto, aproximando-se do ponto crítico o tempo de equilibração típico aumenta embora sua derivada em relação ao potencial químico diverge com um expoente igual à -1/2. Encontramos também um modo não-hidrodinâmico puramente imaginário no canal de difusão vetorial com potencial químico não-nulo que dita o tempo de equilibração neste canal próximo do ponto crítico.

Um das mikroskopische Verhalten der Gravitation zu beschreiben, ist es nötig, Quantenfeldtheorie und allgemeine Relativitätstheorie in einer vereinheitlichten Sprache zu formulieren. Eine Möglichkeit dieses Problem anzugehen ist es, die Punktteilchen der Quantenfeldtheorie durch fadenförmige Strings zu ersetzen. Allerdings erfordert die mathematische Konsistenz, dass sich die String in höherdimensionalen Raum-Zeiten bewegen; dies macht es jedoch sehr schwer, physikalische Konsequenzen zu extrahieren. Eine mögliche Lösung dieses Problems ist die Verwendung von String-Dualitäten, welche die Stringtheorie mittels holographischer Beschreibungen mit Eichtheorien auf dem Rand der Raum-Zeit verbinden. Die Dualitäten sind begründete Vermutungen, die die String- und Eichtheorie bei unterschiedlichen Werten der Kopplung gleichsetzen. Nicht zuletzt deshalb ist eine direkte Überprüfung der Dualitäten schwierig durchführbar. Hier hilft jedoch die sehr bemerkenswerte Tatsache, dass eine verborgene Eigenschaft der Vermutungen Integrabilität zu sein scheint, welche eine Extrapolation zwischen starker und schwacher Kopplung ermöglicht. Desweiteren kann das gesamte Spektrum, in gewissen vereinfachenden Grenzfällen, durch einen kompakten Satz von Bethe-Gleichungen ausgedrückt werden. Die Bethe-Gleichungen, welche aus Eichtheorierechnungen hergeleitet und geraten werden, bieten ein exzellentes Hilfsmittel, die vermuteten Dualitäten zu prüfen. Durch das Vergleichen der Vorhersagen der Gleichungen und expliziten Berechnungen in der Stringtheorie erhält man starke Argumente für die Gültigkeit der Vermutung und der angenommenen Integrabilität. / In this thesis we study superstring theory on AdS$_5\, \times\,$S$^5$, AdS$_3\,\times\,$S$^3$ and $\adsfour$. A shared feature of each theory is that their corresponding symmetry algebras allows for a decomposition under a $\mathbb{Z}_4$ grading. The grading can be realized through an automorphism which allows for a convenient construction of the string Lagrangians directly in terms of graded components. We adopt a uniform light-cone gauge and expand in a near plane wave limit, or equivalently, an expansion in transverse string coordinates. With a main focus on the two critical string theories, we perform a perturbative quantization up to quartic order in the number of fields. Each string theory is, through holographic descriptions, conjectured to be dual to lower dimensional gauge theories. The conjectures imply that the conformal dimensions of single trace operators in gauge theory should be equal to the energy of string states. What is more, through the use of integrable methods, one can write down a set of Bethe equations whose solutions encode the full spectral problem. One main theme of this thesis is to match the predictions of these equations, written in a language suitable for the light-cone gauge we employ, against explicit string theory calculations. We do this for a large class of string states and the perfect agreement we find lends strong support for the validity of the conjectures.

In the present project we study compactifications of type IIA/IIB string theories on toroidal orbifolds. We present the moduli space for N=1 four-dimensional reductions and its topological properties. To fix the value of all moduli, we will construct the most general holomorphic superpotential W using a set of T-dual iterations for the fluxes. Using a 3-torus toy-model, we will give an introductory description to the background of these generalised fluxes.

Depuis la prise de possession de la Nouvelle-Calédonie par la France en 1853, les tensions entre les autochtones et les allochtones ont toujours existé car cet archipel met en présence deux mondes qui se côtoient tout en s’ignorant. À une bipolarisation ethnique naturellement imparfaite entre les populations mélanésiennes et les colonisateurs, s’ajoute également une bipolarisation sociologique, politique, économique et sociale.Dès 1970, la majeure partie de la population mélanésienne de Nouvelle-Calédonie lutte pour une reconnaissance et une revalorisation de son identité culturelle et de son patrimoine, et c’est avec « Melanesia 2000 » en 1975 que le ciment culturel prend corps et avec le foncier que le fondement de la personnalité mélanésienne est affirmé. Les tensions allant crescendo aboutissent au drame d’Ouvéa. Partis d’une situation conflictuelle, les rapports deviennent consensuels avec les Accords de Matignon. La bipolarisation conflictuelle fait place à une bipolarisation contractuelle.La création de trois provinces constitue la première étape de ce long processus d’émancipation. L’Accord de Nouméa et sa loi organique de 1999 poussent la sophistication institutionnelle jusqu’à mettre en place un gouvernement local composé à la proportionnelle des membres du Congrès. Le rééquilibrage concerne les domaines politique, économique et social. En fin d’accord, les calédoniens devront se prononcer sur le transfert des pouvoirs régaliens à la Nouvelle-Calédonie. Comme toutes les élections sont clivées par rapport au concept d’indépendance, les électeurs se basent d’abord sur le positionnement des candidats par rapport à ce concept. L’Accord de Nouméa, de lecture plurielle, obvie les mésententes. Il permet le partage du pouvoir mais laisse en suspend la question essentielle du devenir ultérieur de la Nouvelle-Calédonie. La raison l’a emporté sur la violence, mais les convictions des uns et des autres restent apparemment intactes / Since taking possession of New Caledonia by France in 1853, tensions between natives and immigrants have always existed since the archipelago brings together two worlds that coexist while ignoring each other. At a naturally imperfect polarization between ethnic Melanesian and colonizers, also adds a polarization sociological, political, economic and social.By 1970, most of the Melanesian population of New Caledonia struggle for recognition and appreciation of cultural identity and heritage, and it is with "Melanesia 2000" in 1975 that cement cultural body and takes the property that the basis of personality is Melanesian said. Tensions ranging from tragedy to lead crescendo Uvea. Parties to a conflict situation, the reports become consensual with the Matignon Accords. The bipolar conflict gives way to a polarization of contract. The creation of three provinces is the first step in this long process of emancipation. The Noumea Accord and its organic law of 1999 to push the sophistication institutional set up a local government comprising proportional congressmen. Rebalancing for the political, economic and social development. At the end of agreement, the Caledonian will decide on the transfer of sovereign powers to New Caledonia. Like all elections are cleaved from the concept of independence, voters rely first on the positioning of candidates compared to that concept. The Noumea Accord, reading plural obviates the disagreements. It allows the sharing of power but leaves the key issue of suspending further becoming of New Caledonia. The reason has prevailed over violence, but the convictions of each others apparently remain intact

O estudo de teorias de calibre não-Abelianas fortemente acopladas, em especial de aspectos térmicos e fora do equilíbrio, é um problema central para a compreensão da Cromodinâmica Quântica (Quantum Chromodynamics - QCD) - em particular, para entender a evolução do Plasma de Quarks e Glúons (Quark-Gluon Plasma- QGP). A técnica mais promissora, QCD na rede, obteve sucesso ao tratar de fenômenos no vácuo e em equilíbrio térmico, como espectros e termodinâmica, mas enfrenta desafios consideráveis ao lidar com fenômenos fora do equilíbrio. Uma ferramenta adaptada para lidar com problemas envolvendo plasmas fortemente acoplados em tempo real é a dualidade gauge/gravity, que mapeia uma Teoria Quântica de Campos (Quantum Field Theory - QFT) fortemente acoplada em d dimensões em uma teoria de gravitação em d + 1 dimensões, a qual, de modo geral, é mais fácil de ser resolvida. Nesta tese, estudamos diversas aplicações da dualidade gauge/gravity em teorias não-Abelianas fortemente acopladas que modelam qualitativamente o QGP. Nós estudamos o cálculo holográfico do potencial entre um par quark-antiquark pesado (QQ) para dipolos QQ estáticos e se movendo com relação ao plasma, apresentando um formalismo geral para o cálculo da parte real e imaginária para uma grande classe de teorias gravitacionais duais. Um estudo da massa de Debye holográfica, baseado no maior comprimento de correlação de operadores ímpares por transformações de CT, foi empreendido, com aplicações em modelos bottom-up que reproduzem a termodinâmica da teoria de Yang-Mills SU(Nc) pura e da QCD. Para estes modelos, também calculamos vários coeficientes de transporte associados com o transporte de cargas no plasma, como a condutitividade elétrica, a constante de difusão de carga e coeficientes de transporte associados a uma teoria de hidrodinâmica relativística de segunda ordem. / The study of strongly coupled non-Abelian gauge theories, especially concerning their thermal and non-equilibrium aspects, is a central problem for understanding Quantum Chromodynamics (QCD) - in particular, to understand the evolution of the Quark-Gluon Plasma (QGP). The most successful approach, lattice QCD, succeeds in dealing with vacuum and equilibrium phenomena, such as spectra and thermodynamics, but faces a considerable challenge when it comes to with non-equilibrium phenomena. A tool adapted to deal with real time problems in strongly coupled plasmas is the gauge/gravity, which maps a strongly coupled d dimensional Quantum Field Theory (QFT) to a d + 1 dimensional theory of gravity, which, in general, is easier to solve. In this thesis, we study several applications of the gauge/gravity duality to strongly coupled non-Abelian theories which model qualitatively the QGP. We deal with the holographic evaluation of the heavy quark-antiquark (Q Q) potential for static and moving QQ dipoles, presenting a general formalism for the computation of the real and imaginary parts for a large class of dual theories of gravity. A study of the holographic Debye mass, based on the largest screening length of CT-odd operators, is pursued, with applications on bottom-up holographic models that reproduce the thermodynamics of pure SU(Nc) Yang-Mills theory and QCD. For these models, we also compute several transport coefficients associated with charge transport in the plasma, such as the electric conductivity, the charge diffusion constant, and transport coefficients associated with a theory of second order relativistic hydrodynamics.

Online Convex Optimization (OCO) is a field in the intersection of game theory, optimization, and machine learning which has been receiving increasing attention due to its recent applications to a wide range of topics such as complexity theory and graph sparsification. Besides the usually simple description and implementation of OCO algorithms, a lot of this recent success is due to a deepening of our understanding of the OCO setting and their algorithms by using cornerstone ideas from convex analysis and optimization such as the powerful results from convex duality theory. In this text we present a mostly self-contained introduction to the field of online convex optimization. We first describe the online learning and online convex optimization settings, proposing an alternative way to formalize both of them so we can make formal claims in a clear and unambiguous fashion while not cluttering the readers understanding. We then present an overview of the main concepts of convex analysis we use, with a focus on building intuition. With respect to algorithms for OCO, we first present and analyze the Adaptive Follow the Regularized Leader (AdaFTRL) together with an analysis which relies mainly on the duality between strongly convex and strongly smooth functions. We then describe the Adaptive Online Mirror Descent (AdaOMD) and the Adaptive Dual Averaging (AdaDA) algorithms and analyze both by writing them as special cases of the AdaFTRL algorithm. Additionally, we show simple sufficient conditions for Eager and Lazy Online Mirror Descent (the non-adaptive counter-parts of AdaOMD and AdaDA) to be equivalent. We also present the well-known AdaGrad and Online Newton Step algorithms as special cases of the AdaReg algorithm, proposed by Gupta, Koren, and Singer, which is itself a special case of the AdaOMD algorithm. We conclude by taking a bird\'s-eyes view of the connections shown throughout the text, forming a ``genealogy\'\' of OCO algorithms, and discuss some possible path for future research. / Otimização Convexa Online (OCO) é uma área na intersecção de teoria dos jogos, otimização e aprendizado de máquina que tem recebido maior atenção recentemente devido a suas recentes aplicações em uma grande gama de áreas como complexidade computacional e esparsificação de grafos. Além dos algoritmos de OCO usualmente terem descrições diretas e poderem ser implementados de forma relativamente simples, muito do recente sucesso da área foi possível graças a um melhor entendimento do cenário e dos algoritmos de OCO que se deu com uso de conhecidas ideias de análise e otimização convexa como a poderosa teoria de dualidade convexa. Nesse texto nós apresentamos uma introdução (em sua maioria auto-contida) à área de otimização convexa online. Primeiro, descrevemos os cenários de aprendizado online e de otimização convexa online, propondo uma forma alternativa de formalizar ambos os modelos de forma que conseguimos enunciar afirmações claras e formais de forma que não atrapalha o entendimento do leitor. Nós então apresentamos um resumo dos principais conceitos e resultados de análise convexa que usamos no texto com um foco em criar intuição sobre os mesmos. Com relação a algoritmos para OCO, nós começamos apresentando o algoritmo Adaptive Follow the Regularized Leader (AdaFTRL) e analisamos sua eficácia com um resultado sobre a dualidade de funções strongly convex e strongly smooth. Na sequência, descrevemos os algoritmos Adaptive Online Mirror Descent (AdaOMD) e Adaptive Dual Averaging (AdaDA), analisando a eficácia de cada um escrevendo eles como instâncias do algoritmo AdaFTRL. Além disso, nós mostramos condições simples para que as versões Eager e Lazy do Online Mirror Descent (que são as versões não adaptativas do AdaOMD e do AdaDA, respectivamente) sejam equivalentes. Também apresentamos os algoritmos AdaGrad e Online Newton Step, bem conhecidos na literatura sobre OCO, como casos especiais do algoritmo AdaReg, esse último um algoritmo proposto por Gupta, Koren, and Singer, que, por sua vez, é um caso especial do algoritmo AdaOMD. Nós concluímos o texto com uma visão global das conexões entre os algoritmos que mostramos durante o texto, formando uma \"genealogia\" de algoritmos para OCO, além de discutirmos possíveis direções futuras de pesquisa.

L’œuvre poétique de Sophia de Mello Breyner Andresen, impliquée dans les transformations de la vie politique et sociale du Portugal est indissociable de la qualité de ses choix éthiques, alors même qu'elle atteint à des sommets de poésie pure apparemment inaccessibles à l’analyse. Notre effort porte sur la liaison des aspects qui font la « mythicité » de l’œuvre et nous avons choisi, pour sens de mythique : parole qui se répète, et se différencie dans l’acte de répétition. Notre domaine a donc été une poétique de l’énonciation, soulignant la singularité de chaque poème, inséré dans la continuité du discours. Ainsi, nous pouvions confronter des poèmes exemplifiant des concepts opposés en apparence. L’expérience d’un sacré immanent aux paysages, l’utilisation littéraire et pragmatique de la mythologie ne s’opposent pas à une réflexion critique sur les mythes de notre temps. La plénitude d’un langage qui dit « le nom des choses » coexiste avec la grande diversité des formes poétiques explorées par la poétesse. Le schème répétition/différence est aussi celui du dialogisme qui fait participer la poétesse à la mythicité de ses prédécesseurs. L’expérience du sentiment océanique, immersion initiatique de l’individu dans une totalité, est pour nous le mythe – au sens de narration sacrée d’une origine – de la vocation de notre auteur. Mais la poétesse présente aussi dans sa diversité son assomption à l’ « entièreté de l’être » à partir d’une dualité douloureuse, le fait de vivre un Temps divisé. La « substance du temps », vécue lors de la Révolution d’avril est l’acmé de son œuvre, un discours qui devient mythique dans la mesure où il « fait advenir le peuple ». / The poetic work of Sophia de Mello Breyner Andresen, implied in the transformations of the political life and social of Portugal is bounded to the value of her ethical choices, while at the same time it reaches at tops of pure poetry thus apparently inaccessible to the analysis. Our effort thus relates to the connection of these aspects which make the “mythicity” of work and we chose, for direction of mythical: word which is repeated, and is made different in the act of repetition. Therefore, our field was poetic uttering act underlining the singularity of each poem, inserted in the continuity of the discourse. Thus, we could replace in the whole of the work the poems exemplifying of the concepts opposed seemingly. The experiment of the divine immanent with the landscapes, the literary and pragmatic use of mythology is notopposed to a critical reflection on the myths of our time. The plenitude of a language which says“the name of the things” coexists with the great diversity of the poetic forms explored by the poetess. The pattern repetition/difference is also that of the dialogism which makes the poetesses part in the mythicity of its predecessors. The experiment of the oceanic feeling,initiatory immersion of the individual in a Whole, is for us the myth – within the meaning of sacred narration of an origin – vocation of our author. The poetess also presents, in its diversity her assumption to “entirety of being” starting from a painful duality, the fact of dwelling a divided Time. The “substance of time”, lived at the time of the Revolution of April is the acme of its work, a discourse which becomes mythical insofar as it “makes occur the people”.

<p>The study concentrates on a particular type of state intervention in social policy. It considers whether policy reforms and subsequent provision of information with regards to the issue of parental leave and part-time work arrangements, makes an impact on gender equity in the labour market (Del Boca, 2002 / Naldini &amp / Saraceno, 2008). Giddens&rsquo / theory of structuration is the conceptual framework from which this study approaches these questions. It is thus held that agents (in this instance, women) are constrained by structures (labour policy framework and institutionalised labour practices) to achieve specific social goals. And further: that the apparent lack of power on the part of agents requires intervention on the part of the state apparatus to correct the failure (or inability) of the labour market to deliver the social justice as aspired to in the cited European Employment Strategy, as well as fostering economic efficiency (Barr, 1992). I further contend that not only are agents constrained by structural properties, but that institutional reform (in the form of labour policy reform) is constrained by the human action1 of the management of firms and enterprises as economic agents within the policy framework.</p>

BB som verksamhet har förändrats över tid och är idag en plats där familjen skall kunna vila ut efter förlossningen, i en lugn och trygg miljö. Att fadern på olika sätt är delaktig kring sitt barn främjar faderskapet. Syftet med studien var att beskriva förstagångsfäders upplevelser av delaktighet på BB efter en normal förlossning. För att undersöka fenomenet valdes en deskriptiv, fenomenologisk metod enligt Giorgi. Halvstrukturerade intervjuer genomfördes med tio förstagångsfäder i åldrarna tjugotre till fyrtioett år. Utifrån det insamlade materialet identifierades fyra teman i analysen. En inre kärna, den så kallade essensen, fastställdes och den benämndes Dubbelhet - Familjeinriktad eller mor- och barninriktad? När familjen anländer till BB efter en normal förlossningen uppträder en tvetydighet och förutsättningarna för faderns möjlighet till delaktighet förändras. Att få vara närvarande med sin familj på BB upplevdes som något positivt av fäderna och flera ansåg att det borde vara en självklarhet att få den möjligheten. Organisatoriska faktorer orsakade en känsla av utanförskap hos fäderna. Personalens bemötande och mannens eget intresse hade betydelse för hur fäderna upplevde graden av delaktighet.

Non-linear sigma models with extended supersymmetry have constrained target space geometries, and can serve as effective tools for investigating and constructing new geometries. Analyzing the geometrical and topological properties of sigma models is necessary to understand the underlying structures of string theory. The most general two-dimensional sigma model with manifest N=(2,2) supersymmetry can be parametrized by chiral, twisted chiral and semichiral superfields. In the research presented in this thesis, N=(4,4) (twisted) supersymmetry is constructed for a semichiral sigma model. It is found that the model can only have additional supersymmetry off-shell if the target space has a dimension larger than four. For four-dimensional target manifolds, supersymmetry can be introduced on-shell, leading to a hyperkähler manifold, or pseudo-supersymmetry can be imposed off-shell, implying a target space which is neutral hyperkähler. Different sigma models and corresponding geometries can be related to each other by T-duality, obtained by gauging isometries of the Lagrangian. The semichiral vector multiplet and the large vector multiplet are needed for gauging isometries mixing semichiral superfields, and chiral and twisted chiral superfields, respectively. We find transformations that close off-shell to a N=(4,4) supersymmetry on the field strengths and gauge potentials of the semichiral vector multiplet, and show that this is not possible for the large vector multiplet. A sigma model parametrized by chiral and twisted chiral superfields can be related to a semichiral sigma model by T-duality. The N=(4,4) supersymmetry transformations of the former model are linear and close off-shell, whereas those of the latter are non-linear and close only on-shell. We show that this discrepancy can be understood from T-duality, and find the origin of the non-linear terms in the transformations.