Diese Doktorarbeit behandelt quantentheoretische Aspekte von Typ II Superstringtheorien in AdS5xS5- und AdS4xCP3-Hintergründen für die AdS/CFT Korrespondenz. Dabei werden perturbative Methoden und Verfahren der Gitterfeldtheorie benutzt. Die Konstruktion des Supercoset-Sigma-Modell für Strings im AdS5xS5wird skizziert, während die generelle Quantendynamik des Superstring in AdS4xCP3 mit Hilfe einer dimensionaler Reduktion der Supermembrane-Wirkung in AdS4xS7 beschrieben wird. Ein manifest kovarianter Formalismus zur semi-klassischen Quantisierung von Strings um beliebige Minimalflächen in AdS5xS5 wird präsentiert, der durch die Darstellung der Fluktuationsoperatoren in Form von intrinsischen und extrinsischen Varianten der Hintergrundgeometrie erreicht wird. Eine Verallgemeinerung der Lame-Differentialgleichung zur 4. Ordnungwird mit Hilfe der Spektralmethode exakt gelöst. Dadurch konnten in 1-Schleifennäherung die Energie des String im SU(2)-Sektor, im Grenzfall beschrieben durch ein Quantum-Landau-Lifshitz-Modell, und der bosonische Beitrag zur Energie des in AdS5 und S5 rotierenden String bestimmt werden. In ähnlicher Weise erhält man in 1-Schleifennäherung den ¼-BPS-Latitude Wilson-Loop in N=4-SYM-Theorie normiert durch den ½-BPS-Loop. Das Regularisierungsschema reproduziert die Vorhersage aus supersymmetrischer Lokalisierung bis auf einen Rest, welcher diskutiert wird. Außerdem wird die Wirkung des AdS4xCP3-String, entwickelt um den null-cusp Hintergrund, studiert und die Cusp-Anomalie in 2-Schleifennäherung berechnet. Das Ergebnis stimmt mit dem vermuteten exakten Ausdruck, der ABJM-Interpolationsfunktion, überein. Schließlich wird die AdS5xS5-Superstringtheorie in AdS-Lichtkegel-Eichung diskretisiert und mit Monte-Carlo-Algorithmen Gittersimulationen bei endlicher Kopplung durchgeführt. Dabei werden die Stringwirkung, aus der mit Hilfe von AdS/CFT die null-cusp anomale Dimension von N=4 SYM extrahiert werden kann, und die Masse einer AdS Anregung bestimmt. / This thesis discusses quantum aspects of type II superstring theories in AdS5xS5 and AdS4xCP3 backgrounds relevant for the AdS/CFT correspondence, using perturbative methods at large string tension and lattice field theory techniques inspired by a work of Roiban and McKeown. We review the construction of the supercoset sigma-model for strings in the AdS5xS5 background, whereas the general quantum dynamics of the superstring in AdS4xCP3 is described by a double dimensional reduction of the supermembrane action in AdS4xS7. We present a manifestly covariant formalism for semiclassical quantization of strings around arbitrary minimal-area surfaces in AdS5xS5, expressing the fluctuation operators in terms of intrinsic and extrinsic invariants of the background geometry. We exactly solve the spectral problem for a fourth-order generalization of the Lame'' differential equation with doubly periodic coefficients in a complex variable. This calculates the one-loop energy of the (J1,J2)-string in the SU(2) sector in the limit described by a quantum Landau-Lifshitz model and the bosonic contribution to the energy of the (S,J)-string rotating in AdS5 and S5. Similar techniques calculate the 1/4-BPS latitude Wilson loops in N=4 SYM theory at one loop, normalized to the 1/2-BPS circular loop. Our regularization scheme reproduces the next-to-leading order predicted by supersymmetric localization, up to a remainder function that we discuss upon. We also study the AdS4xCP3 string action expanded around the null cusp background and compute the cusp anomaly up to two loops. This agrees with an all-loop conjectured expression of the ABJM interpolating function. We finally discretize the AdS5xS5 superstring theory in the AdS light-cone gauge and perform lattice simulations at finite coupling with a Monte Carlo algorithm. We measure the string action, from which we extract the null cusp anomalous dimension of N=4 SYM as derived from AdS/CFT, as well as the mass of an AdS excitation.

Der Gegenstand dieser Arbeit ist Bestandteil der Stringtheorie und betrifft insbesondere die geometrischen Aspekte der Realisierung von Eichtheorien innerhalb der Stringtheorie. Wir studieren die Eichtheorie von D3-Branes an verallgemeinerten Singularitaeten wie der Orbifold- oder Conifold-Singularitaet. Die Einfuehrung der sogenannten Branediamanten fuehrt auf ein konsistentes Bild. Fuer diese Klasse von Modellen wird die Wirkung der Mirrorsymmetrie diskutiert. Im zweiten Teil untersuchen wir die Feldtheorie der M5-Brane auf der Grundlage des Supereinbettungsformalismus. Das Hauptresultat dieses Kapitels ist eine explizite Identifikation der selbstdualen 3-Form mit den Parametern der komplexen Struktur des Einbettungsraumes. Das heuristische Material, das in den vorangegangenen Kapiteln angesammelt wurde, weist darauf hin, dass die Informationen, die ein supersymmetrischer 3-Zykel enthaelt, zumindest teilweise auf supersymmetrische 2-Zykel zurueckgefuehrt werden koennen. Daher studieren wir den Fall von Brane-Boxen, die durch Ueberlagerung von gewoehnlichen N=2 Systemen aus D4 und NS5-Branes gewonnen werden koennen. Diese Konfigurationen erfuellen die Bedingung des `uniform bending' und der Lift auf einen supersymmetrischen 3-Zykel kann explizit ausgefuehrt werden. Im letzten Teil konstruieren wir eine neue superkonforme N=1 Eichtheorie, die aus einer Massendeformation der N=4 SYM entsteht und eine duale Supergravitationsbeschreibung durch die AdS/CFT-Korrespondenz besitzt. / The subject of this work is part of the theory of strings and in particular concerned with geometrical aspects of the realization of gauge theory within string theory. In particular we study the gauge theory of D3-branes at generalised singularities like orbifolds and the orbifolded conifold singularities. The introduction of the so called diamonds leads to a consistent picture. The action of mirror symmetry for this class of models is discussed. In a second part the field theory of the M5-brane will be investigated on the basis of the superembedding approach. The main result here will be a rather explicit identification of the self dual three form field with the parameters of the complex structure of the embedding space. The heuristic material collected from the previous chapters states that the information contained in supersymmetric 3-cycles can be partially extracted from supersymmetric 2-cycles. Thus we study the case of brane boxes, which can be obtained by sewing together usual N=2 setups of D4 and NS5-branes. These systems satisfy the condition of uniform bending and the lift to a supersymmetric 3-cycle can be performed explicitly. In the last part a new superconformal N=1 gauge theories will be constructed which arise as certain deformations of N=4 SYM and have a dual description due to the AdS/CFT correspondence.

Diese Arbeit beschäftigt sich mit drei Aspekten der AdS/CFT-Korrespondenz, die alle einen Schritt über die klassische SUGRA-Näherung hinausgehen. Zuerst diskutieren wir den BMN Grenzfall der Korrespondenz und untersuchen insbesondere das Verhalten der quantenfeldtheoretischen Propagatoren. Dabei weisen wir nach, dass die Propagatoren im für den BMN Fall relevanten Hintergrund ebener Wellen semiklassisch (WKB) exakt beschrieben werden. Danach wird im Rahmen der AdS/CFT-Korrespondenz der Grenzfall verschwindender Kopplung der konformen Feldtheorie betrachtet. Zur technischen Vereinfachung geschieht dies für das Beispiel des O(N)-Vektormodells. Dabei wird die OPE der Vierpunktfunktionen so umgeschrieben, dass sie strukturelle Ähnlichkeit mit Witten-Diagrammen einer korrespondierenden Theorie von Strömen mit höherem Spin hat. Außerdem wird das O(N)- Vektormodell bei großem N am wechselwirkenden Infrarot-Fixpunkt untersucht. Im letzten Punkt wenden wir uns schließlich der ursprünglichen AdS/CFTDualität unter Mitnahme der nächstführenden Ordnung der 1/N-Entwicklung zu. Für die Deformationen der CFT durch relevante Doppelspur-Operatoren finden wir bei Zustandssummen und konformen Anomalien exakte Übereinstimmung zwischen direkter und AdS-seitiger indirekter Rechnung. Damit wird ein nicht trivialer Test der Korrespondenz über die SUGRA-Näherung hinaus erbracht. / This thesis deals with three corners of the AdS/CFT Correspondence that lie one step beyond the classical supergravity (SUGRA) approximation. We first explore the BMN limit of the duality and study, in particular, the behavior of field theoretic propagators in the corresponding Penrose limit. We unravel the semiclassical (WKB-) exactness of the propagators in the resulting plane wave background metric. Then, we address the limit of vanishing coupling of the conformal field theory (CFT) at large N. In the simplified scenario of Higher Spin/O(N) Vector Model duality, the conformal partial wave (CPW) expansion of scalar four-point functions are reorganized to make them suggestive of a bulk interpretation in term of a consistent truncated massless higher spin theory and their corresponding exchange Witten graphs. We also explore the connection to the interacting O(N) Vector Model at its infra-red fixed point, at leading large N. Finally, coming back to the gauge theory, we study the effect of a relevant double-trace deformations of the boundary CFT on the partition function and its dual bulk interpretation. We show how the one-loop computation in the Anti-de Sitter (AdS) space correctly reproduces the partition function and conformal anomaly of the boundary theory. In all, we get a clean test of the duality beyond the classical SUGRA approximation in the AdS bulk and at the corresponding next-to-leading 1/N order of the CFT at the conformal boundary.

In der vorliegenden Arbeit werden versteckte Symmetrien innnerhalb der N=4 supersymmetrischen Yang--Mills Theorie oder der nach der AdS/CFT Korrespondenz dualen Beschreibung durch eine String-Theorie in AdS5 x S5 besprochen. Dabei betrachten wir die Maldacena--Wilson Schleife, die sich für diese Untersuchungen besonders eignet, da ihr Vakuum-Erwartungswert für glatte Kurven nicht divergiert und die vermutete Dualität zu Streuamplituden wenigstens konzeptionell eine Möglichkeit bietet, etwaige Symmetrien zu anderen Observablen zu übertragen. Ihre Beschreibung durch Minimalflächen in AdS5 erlaubt es, Symmetrien mithilfe der Integrabilität der zugrunde liegenden klassischen String-Theorie zu konstruieren. Dieser Zugang wurde bereits in der Herleitung der Yang'schen Symmetrie der Maldacena--Wilson Schleife bei starker Kopplung sowie in der Beschreibung von Deformationen gleiches Flächeninhalts von Minimalflächen in AdS3 verwendet. Diese beiden Ergebnisse werden in der vorliegenden Arbeit miteinander verbunden und erweitert. Im Sinne einer systematischen Herangehensweise besprechen wir zunächst die Symmetriestruktur der zugrunde liegenden String-Theorie. Diese Diskussion lässt sich auf die Diskussion von String-Theorien in symmetrischen Räumen verallgemeinern. Dabei zeigt sich, dass die Symmetrie, welche die Deformationen gleiches Flächeninhalts in AdS3 erzeugt, in der Symmetriestruktur dieser Modelle eine zentrale Rolle einnimmt: Sie wirkt als Aufsteige-Operator auf den unendlich vielen erhalten Ladungen und generiert somit den Spektralparameter. Weiterhin lässt sie sich anwenden, um ausgehend von der globalen Symmetrie sämtliche Symmetrien des zugrunde liegenden Modells zu konstruieren. Sie wird daher als die Master-Symmetrie dieser Modelle bezeichnet. Zusätzlich wird die Algebra der Symmetrie-Variationen sowie der erhaltenen Ladungen ausgearbeitet. Für den konkreten Fall von Minimalflächen in AdS5 diskutieren wir die Deformation der Minimalflächenlösung für den Fall eines lichtartigen Vierecks. Diese liefert die duale Beschreibung der Streuamplitude für vier Gluonen. Damit unternehmen wir einen ersten Schritt zur Übertragung der Master-Symmetrie auf Streuamplituden. Weiterhin berechnen wir die Variation der Randkurven der Minimalflächen unter der Master- und Yang'schen Symmetrie für allgemeine, glatte Randkurven. Das Ergebnis dieser Rechnung führt auf eine Verallgemeinerung der Master-Symmetrie zu einer Variation, die von der Kopplungskonstanten abhängt und für beliebige Werte der Kopplungskonstanten eine Symmetrie der Maldacena--Wilson Schleife darstellt. Unsere Diskussion erklärt das Scheitern vorheriger Versuche, die entsprechende Symmetrie im Spezialfall von Minimalflächen in AdS3 zu schwacher Kopplung zu übertragen. Wir besprechen verschiedene Ansätze, die Yang'sche Symmetrie zu schwacher oder beliebiger Kopplung zu übertragen, schlussfolgern aber letztendlich, dass eine Yang'sche Symmetrie der Maldacena--Wilson Schleife nicht vorzuliegen scheint. Die Situation ändert sich, wenn wir Wilson Schleifen in Superräumen betrachten. Diese sind die natürlichen supersymmetrischen Erweiterungen der Maldacena--Wilson Schleife. Für die Yang'sche Invarianz ihres Vakuum-Erwartungswerts wurden wichtige Anhaltspunkte gefunden und sowohl die Beschreibung dieser Operatoren als auch der Beweis der Yang'schen Invarianz bei schwacher Kopplung wurden parallel zur Arbeit an der vorliegenden Dissertation vervollständigt. Wir diskutieren das Gegenstück zu diesem Ergebnis bei starker Kopplung. Dort wird die Wilson Schleife durch eine Minimalfläche beschrieben, welche im Superraum der Superstring-Theorie vom Typ IIB in AdS5 x S5 liegt. Der Vergleich der bei starken Kopplung etablierten Invarianz mit den entsprechenden Generatoren bei schwacher Kopplung zeigt, dass die Symmetrie-Generatoren einen lokalen Anteil enthalten, der auf nicht-triviale Weise vom Wert der Kopplungskonstanten abhängt. Zusätzlich finden wir sogenannte Bonus-Symmetrien. Diese sind die analogen Generatoren in den höheren Ordnungen zum Hyperladungs-Generator, der selbst keine Symmetrie darstellt. Wir zeigen, dass diese Symmetrien in allen höheren Ordnungen der Yang'schen Algebra vorliegen. / This thesis discusses hidden symmetries within N=4 supersymmetric Yang--Mills theory or its AdS/CFT dual, string theory in AdS5 x S5. Here, we focus on the Maldacena--Wilson loop, which is a suitable object for this study since its vacuum expectation value is finite for smooth contours and the conjectured duality to scattering amplitudes provides a conceptual path to transfer its symmetries to other observables. Its strong-coupling description via minimal surfaces in AdS5 allows to construct the symmetries from the integrability of the underlying classical string theory. This approach has been utilized before to derive a strong-coupling Yangian symmetry of the Maldacena--Wilson loop and describe equiareal deformations of minimal surfaces in AdS3. These two findings are connected and extended in the present thesis. In order to discuss the symmetries systematically, we first discuss the symmetry structure of the underlying string model. The discussion can be generalized to the discussion of generic symmetric space models. For these, we find that the symmetry which generates the equiareal deformations of minimal surfaces in AdS3 has a central role in the symmetry structure of the model: It acts as a raising operator on the infinite tower of conserved charges, thus generating the spectral parameter, and can be employed to construct all symmetry variations from the global symmetry of the model. It is thus referred to as the master symmetry of symmetric space models. Additionally, the algebra of the symmetry variations and the conserved charges is worked out. For the concrete case of minimal surfaces in AdS5, we discuss the deformation of the four-cusp solution, which provides the dual description of the four-gluon scattering amplitude. This marks the first step toward transferring the master symmetry to scattering amplitudes. Moreover, we compute the master and Yangian symmetry variations of generic, smooth boundary curves. The results leads to a coupling-dependent generalization of the master symmetry, which constitutes a symmetry of the Maldacena--Wilson loop at any value of the coupling constant. Our discussion clarifies why previous attempts to transfer the deformations of minimal surfaces in AdS3 to weak coupling were unsuccessful. We discuss several attempts to transfer the Yangian symmetry to weak or arbitrary coupling, but ultimately conclude that a Yangian symmetry of the Maldacena--Wilson loop seems not to be present. The situation changes when we consider Wilson loops in superspace, which are the natural supersymmetric generalizations of the Maldacena--Wilson loop. Substantial evidence for the Yangian invariance of their vacuum expectation value has been provided at weak coupling and the description of the operator as well as its weak-coupling Yangian invariance were subsequently established in parallel to the work on this thesis. We discuss the strong-coupling counterpart of this finding, where the Wilson loop in superspace is described by minimal surfaces in the superspace of type IIB superstring theory in AdS5 x S5. The comparison of the strong-coupling invariance derived here with the respective generators at weak coupling shows that the generators contain a local term, which depends on the coupling in a non-trivial way. Additionally, we find so-called bonus symmetry generators. These are the higher-level recurrences of the superconformal hypercharge generator, which does not provide a symmetry itself. We show that these symmetries are present in all higher levels of the Yangian.

L'objectif de cette thèse est de proposer de nouvelles approches plus efficaces pour améliorer la situation du trafic aérien dans l'Atlantique Nord (NAT). NAT est considéré comme l'espace aérien océanique le plus utilisé dans le monde. Le contrôle du trafic aérien dans cet espace confronte plusieurs difficultés dues aux différences de fuseaux horaires, aux demandes des passagers et aux vents forts induits par les jet-streams. De plus, la prédiction et le contrôle des trajectoire de vol sont très limités à cause de l'abscence de couverture radar. Par conséquent, une structure de routes, appelée Organized Track System (OTS), est établie dans le NAT et des normes de séparation très rigide sont imposés. Tous ces facteurs obligent les vols à suivre des trajectoires non optimales, ce qui influence négativement la consommation de carburant et le coût total du vol. Dans le cadre des projet lancé pour moderniser le systéme de gestion du trafic aérien, de nouvelles technologie de communication, de navigation et de surveillance ont été développés, l'un des plus prometteurs étant l'ADS-B. L'utilisation de l'ADS-B permet d'exploiter de nouvelles et différentes méthodes d'organiser le trafic, alternative à l'OTS, ce qui constitue l'axe principal de notre travail. Tout d'abord, nous étudions la possibilité d'introduire le Free Flight Concept (FFC) dans le NAT. En effet, nous proposons une nouvelle approche pour organiser le trafic aérien NAT en se basant sur un comportement d'essaim. En effet, le trafic est considéré comme un système Multi-Agent où tous les vols coopèrent, grâce à l'ADSB, afin de construire leurs trajectoires, tout en détectant et en résolvant les conflits entre eux. Les trajectoires résultantes sont efficaces en terme de temps de croisière. Cependant, ils ne sont pas robustes contre les changements du vents. Ensuite, nous proposons une nouvelle structure de route qui bénéficie du jet stream. Cette structure de route est appelée Wind-Optimal Track Network (WOTN), et est construite en considérant les normes de séparation réduites. WOTN couvre un plus grand espace aérien que l'OTS, afin de gérer un trafic plus dense. En gros, WOTN est construit de telle sorte que des pistes parallèles proches sont mis-en place pour suivre le jet- stream et les transitions entre les pistes n'est autorisé que dans les sections d'entrée et de sortie de la structure. Les résultats révèlent l'importance de mettre en place une structure de route afin de garantir des trajectoires robustes face aux vents forts. Enfin, nous proposons une approche permettant aux aéronefs de sortir en toute sécurité de la structure de la route en cas d'urgence. / The objective of the present thesis is to propose new more efficient trends to improve the air traffic situation over the North Atlantic (NAT) airspace. In fact, the NAT is considered to be the most congested oceanic airspace in the world. For many years, air traffic control in this airspace has experienced many difficulties caused by the time zone differences, passenger demands and strong winds induced by the jet streams. This leads to high congestion in the airspace especially at peak hours. Furthermore, flight trajectory prediction and control are very limited due to the lack of radar coverage in oceanic airspace. To support conflict-free flight progress, a structure of routes, called Organized Track System (OTS), is established in the NAT and very restrictive separation standards are applied. These rigid rules oblige flights to follow non-optimal trajectories, which negatively influences the fuel consumption and the total flight cost. In order to guarantee efficient traffic separation in the context of ever increasing trafic density, alternative means of communication, navigation and surveillance were developed and progressively be implemented, one of the most promising being the Automatic Dependent Surveillance-Broadcast (ADS-B). The widespread use of ADS-B makes it possible to organize traffic in new ways, as an alternative to the OTS, which is the main focus of the current work. First of all, we investigate the possibility of introducing the Free Flight Concept (FFC) in NAT. Indeed, we present an approach to construct and organize NAT traffic based on a swarm behavior. Here, the traffic is considered as a Multi-Agent system where all flights cooperate, thanks to ADS-B equipage, in order to construct their trajectories, while detecting and resolving conflicts between each other. The resulting trajectories are efficient in term of cruise time. However, they are not robust regarding changing winds. Next, we propose a new route structure for eastbound NAT traffic that benefit from the jet stream. This route structure is called Wind-Optimal Track Network (WOTN), and is constructed based on the reduced separation norms. WOTN covers larger airspace than the OTS, in order to handle the growing traffic. Roughly, WOTN is constructed in such a way that nearby parallel tracks are made to follow the jet streams and re-routing between tracks is only allowed in the input and output sections of the structure. Results reveal the importance of implementing a route structure in order to guaranty robust trajectories in the face of strong winds. Finally, we propose an approach to allow aircraft to safely exit the route structure in case of an emergency. The overall methodologies are implemented and tested with eastbound flight data over the NAT. We thereby produce conflict-free and robust trajectory planning for eastbound NAT flights, while benefiting from the reduced separation norms and the jet stream thus proving the efficiency of our approaches.

No description available.

With the rapid advancement of mobile devices, people have become more attached to them than ever. This rapid growth combined with millions of applications (apps) make smartphones a favourite means of communication among users. In general, the available contents on smartphones, apps and the web, come into two versions: (i) free contents that are monetized via advertisements (ads), and (ii) paid ones that are monetized by user subscription fees. However, the resources (energy, bandwidth, processing power) on-board are limited, and the existence of ads in either websites or free apps can adversely impact these resources. These issues brought the need for good understanding of the mobile advertising eco-system and how such limited resources can be efficiently used. This thesis focuses on mobile web browsing. Surfing web-pages on smatphones is one of the most commonly used task among smartphone users. However, web-page complexity is increasing, especially when designed for desktop computers. On one hand, the existence of ads in web-pages is essential for publishers' monetization strategy. On the other hand, their existence in webpages leads to even higher complexity of the webpages. This complexity in the smartphone environment, where the battery and bandwidth resources are limited, is reflected in longer loading time, more energy consumed, and more bytes transferred. With this view, quantifying the energy consumption due to web ads in smartphones is essential for publishers to optimize their webpages, and for system designers to develop an energy-aware applications (browsers) and protocols. Apart from their energy impact, ads consume network bandwidth as well. Therefore, quantifying the bandwidth consumption due to downloading web ads is crucial to creating more energy and bandwidth aware applications. This thesis first classifies web content into: (i) core information, and (ii) forced ``unwanted" information, namely ads. Then, describes an approach that enables the separation of web content in a number of a websites. Having done so, the energy cost due to downloading, rendering, and displaying web ads over Wi-Fi and 3G networks is evaluated. That is, how much energy web ads contribute to the total consumed energy when a user accesses the web. Furthermore, the bandwidth consumed by web ads in a number of well-known websites is also evaluated. Motivated by our findings about ads' impact on the energy and bandwidth, the thesis proposes and implements a novel web-browsing technique that adapts the webpages delivered to smartphones, based on a smartphone's current battery level and the network type. Webpages are adapted by controlling the amount of ads to be displayed. Validation tests confirm that the system, in some cases, can extend smartphone battery life by up to ~ 30\% and save wireless bandwidth up to ~ 44\%.

As an operational approach to the Bekenstein-Hawking formula S_{BH}=A/4l_{Pl}^{2} for the black hole entropy, we consider the reversible contraction of a spinning thin shell to its event horizon and find that its thermodynamic entropy approaches $S_{\mathrm{BH}}$. In this sense the shell, called a "black shell", imitates and is externally indistinguishable from a black hole. Our work is a generalization of the previous result [10] for the spherical case. We assume the exterior space-time of the shell is given by the Kerr metric and match it to two different interior metrics, a vacuum one and a non-vacuum one. We find the vacuum interior embedding breaks down for fast spinning shells. The mechanism is not clear and worth further exploring. We also examine the case of a Kerr-AdS exterior, without trying to find a detailed interior solution. We expect the same behavior of the shell when the horizon limit is approached.

As an operational approach to the Bekenstein-Hawking formula S_{BH}=A/4l_{Pl}^{2} for the black hole entropy, we consider the reversible contraction of a spinning thin shell to its event horizon and find that its thermodynamic entropy approaches $S_{\mathrm{BH}}$. In this sense the shell, called a "black shell", imitates and is externally indistinguishable from a black hole. Our work is a generalization of the previous result [10] for the spherical case. We assume the exterior space-time of the shell is given by the Kerr metric and match it to two different interior metrics, a vacuum one and a non-vacuum one. We find the vacuum interior embedding breaks down for fast spinning shells. The mechanism is not clear and worth further exploring. We also examine the case of a Kerr-AdS exterior, without trying to find a detailed interior solution. We expect the same behavior of the shell when the horizon limit is approached.

Submitted by FERNANDO ENRIQUE SERNA ALGARÍN null (ferse1129@gmail.com) on 2018-01-10T21:52:53Z No. of bitstreams: 1 tese.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) / Approved for entry into archive by Hellen Sayuri Sato null (hellen@ift.unesp.br) on 2018-01-12T15:54:08Z (GMT) No. of bitstreams: 1 algarin_fcs_dr_ift.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) / Made available in DSpace on 2018-01-12T15:54:08Z (GMT). No. of bitstreams: 1 algarin_fcs_dr_ift.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) Previous issue date: 2017-10-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesta tese empregamos um modelo de interação de contato que preserva simetrias para estudar estrututura hadrônica e matéria de quarks. A interação de contato é uma representação de kernels não perturbativos usados em equações de Dyson-Schwinger e Bethe-Salpeter da Cromodinâmica Quântica (QCD). A ideia básica do modelo está baseada num esquema de subtração que evita passos tradicionais no cálculo de de integrais divergentes que invariavelmente levam a violações de simetrias. Em temperatura zero, as equações de Dyson-Schwinger equation para os propagadores dos quarks u; d; s and c são resolvidas e amplitudes de estado ligado de Bethe-Salpeter, que respeitam a invariância sob translações espaço-temporais e as identidades de Ward-Takahashi associadas com simetrias globais da QCD, são obtidas para calcular as massas e as constantes de decaimento eletrofracas dos mésons pseudoscalares π; K, D e Ds e dos mésons vetorias ρ, K*, D* e Ds*. As predições do modelo estão em bom acordo com dados experimentais e da QCD na rede. Em adição, estendemos o modelo para temperaturas diferentes de zero; neste caso, o problema de violação de simetrias está restrito apenas às partes puramente divergentes porque os termos que dependem das distribuições térmicas são finitas e não requerem regularização. Finalmente, investigamos a dependência com a temperatura das contribuições das flutuações quânticas quark-π e quark-σ aos coeficientes de transporte de viscosidade de cisalhamento η e volumétrica ζ e as suas razões com a densidade de entropia s. As larguras térmicas originárias dessas fluctuações são calculadas com o formalismo de teoria de campos a temperatura finita de tempo real. Para esse cálculo, empregamos os resultados obtidos com as equações de Dyson-Schwinger e Bethe-Salpeter para a dependência com a temperatura das massas dos mésons e as contantes de acoplamento quark-méson. Os resultados para as razões η/s and ζ/s estão em bom acordo com resultados com a literatura obtidos com modelos e técnicas diferentes. Em particular, nossos resultados para η/s possuem um mínimo muito próximo ao limite inferior da conjectura AdS/CFT, η/s = 1/4π. / In thesis, a symmetry-preserving contact interaction model is used to study hadron structure and quark matter. The contact interaction is a representation of nonperturbative kernels used in Dyson-Schwinger and Bethe-Salpeter equations of Quantum Chromodynamics (QCD). The basic idea of the model is based on a subtraction scheme that avoids standard steps in the evaluation of divergent integrals that invariably lead to symmetry violation. At zero temperature, the Dyson-Schwinger equation is solved for the u; d; s and c quark propagators and the boundstate Bethe-Salpeter amplitudes respecting spacetime-translation invariance and the Ward-Green-Takahashi identities associated with global symmetries of QCD are obtained to calculate masses and electroweak decay constants of the pseudoscalar π; K, D and Ds and vector ρ, K*, D*, and Ds* mesons. The predictions of the model are in good agreement with available experimental and lattice QCD data. In addition, we extend the model to nonzero temperature; here, the problem of symmetry violation is associated only with the purely divergent parts because the effects due to the termal distributions are finite and do not need regularization. We compute the temperature dependence of the masses and decay constants of the pseudoscalar mesons considered here. Finally, we have investigated the temperature dependence of the contributions of quark-π and quark-σ quantum fluctuations to the transport coefficients of shear η and bulk ζ viscosities and their ratios to the entropy density s. The quark thermal widths originating those fluctuations are calculated with the formalism of real-time thermal field theory. For these calculations, we have used the results obtained via Dyson-Schwinger and Bethe-Salpeter equations for the temperature dependence of constituent quark and meson masses and quark-meson couplings. The results for the ratios η/s and ζ/s are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η/s has a minimum very close to the conjectured AdS/CFT lower bound, η/s = 1/4π. / CNPq:140041/2014-1