In Air Traffic Management (ATM) training, simulations of real air traffic control (ATC) scenarios are a key part of practical teaching. On the internet one may find multiple different ATM simulators available to the public with open source code. Today most aircraft transmit data about position, altitude, and speed into the atmosphere that essentially are unencrypted data points, available to the public. This means that potential attackers could project "fake" ADS-B data and spoof existing data to the air traffic controllers (ATCO) if the right equipment is used. We see this as a security flaw and we want to prepare ATCO for cyberattacks by modifying an ATM simulator with cyberattacks. First, openScope was chosen as the ATM simulator to be modified. Subsequently, three types of attacks were chosen for the simulator to be equipped with, based on ADS-B weaknesses from existing literature: aircraft that do not respond to commands, aircraft with altering positional data, and aircraft with incorrect speed and altitude data. The recorded parameters were the written command lines and corresponding aircraft type it was applied to. Using this modified simulator, ATCO can now be evaluated against cyberattacks. / Inom utbildningen till att bli flygledare finns olika simuleringar av verkliga scenarion och det är en viktig del av lärandet. Idag finns det många olika flygledningssimulatorer som finns tillgängliga för allmänheten med öppen källkod på internet. Idag sänder de flesta flygplan information om position, höjd och hastighet ut i atmosfären som i själva verket är okrypterade datapunkter och är tillgängliga för vem som helst som har rätt teknik tillgänglig. Det är även möjligt att både skicka och ändra denna data. Vi ser detta som en stor säkerhetsbrist och vill förbereda flygledare för olika former av cyberattacker genom att modifiera en tillgänglig simulator. Först valdes simulatorn openScope till att modifieras. Härnäst valdes tre olika former av attacker: flygplan som inte ger svar på kommandon, flygplan som spontant byter position och flygplan som visar felaktig höjd och hastighet. För att analysera användaren valdes det att spara använderans kommandon och attacksorten av flygplanet i fråga. Med hjälp av denna simulator kan flygledare nu utvärderas på deras hantering av cyberattacker.

Pendant les deux dernières décennies l'idée d'une nature holographique de la gravité a pris forme à travers la correspondance AdS/CFT, aussi connue sous le nom de dualité jauge/gravité. CFT correspond à « conformal field theory », théorie conforme des champs, et dans la dualité il s'agit d'une théorie de jauge dans la limite de grand N 1. AdS représente l'espace d'anti-de Sitter, une solution maximalement symétrique des équations d'Einstein avec une constante cosmologique négative, et correspond au côté gravitationnel de la dualité. Dans certaines limites, des théories sur AdS avec de la gravité en d+1 dimensions peuvent être associées à des CFTs sans gravité en d dimensions, d'où le nom « dualité ». Cette dualité est aussi dite « holographique » par analogie avec le concept optique homonyme qui indique la possibilité de générer une image tridimensionnelle comme la projection d'un écran ou d'un film bidimensionnel. Le terme holographie vient des mots grecs holos, « en entier », et graphe, « écriture. Une telle projection, malgré le fait que l'information est stockée en 2 dimensions, contiendrait toute l'information pour reconstruire l'image tridimensionnelle. Dans la dualité jauge/gravité, la théorie de jauge se comporte comme un film d-dimensionnel qui contient la même information que l'image gravitationnelle (d+1)-dimensionnelle. Cette dualité relie la théorie gravitationnelle à la théorie quantique de champs (TQC) dual à travers des conditions aux limites sur des champs qui vivent dans AdS. Dans ce sens-là, la théorie de jauge peut être considérée comme définie sur le bord d'AdS, ce qui renforce l'analogie optique et, pour cela, la dualité est aussi connue comme la correspondance « bulk/boundary » ou « intérieur/bord ». Une de ses principales propriétés est l'association d'une TQC fortement couplée à une théorie gravitationnelle faiblement couplée et vice-versa. Pour cette raison, dans cette thèse j'utilise un intérieur faiblement couplé pour explorer et identifier des propriétés non-perturbatives de TQCs dans la limite de couplage fort. Cette thèse explore l'holographie à température nulle et finie. Nos objets d'intérêt sont des TQCs générées par la brisure de l'invariance d'échelle de CFTs et qui peuvent être étudiées à travers le groupe de renormalisation (GR). Le profil des champs au long de la dimension supplémentaire à l'intérieur est dual à des flots du GR sur la TQC vivant sur le bord, car la dimension supplémentaire est en correspondance avec l'échelle d'énergie. La correspondance va plus loin en identifiant les champs de l'intérieur comme duaux aux couplages renormalisés de la TQC, ce qui mène au concept du GR holographique. Avec le GR holographique, dans cette thèse je vais explorer des comportements qui sont d'une nature intrinsèquement non-perturbatifs du point de vue de la QFT. Les principaux résultats sont les suivants. A température nulle, pour un seul couplage, nous avons classifié toutes les solutions de notre système et identifié trois types de flots exotiques correspondant à des solutions qui inversent leur direction au long du flot, d'autres qui sautent des points fixes et des flots qui interpolent entre des minima du potentiel. Ces résultats ont été généralisés à plusieurs couplages à température nulle. Je présente également la relation entre la fonction principale de Hamilton et la nature du champ de vitesses des couplages: gradient ou non. À température finie nous avons considéré un seul couplage et exploré la thermodynamique des trois types de solutions exotiques mentionnées ci-dessus. Nous avons identifié une transition de phase entre des solutions qui sautent et qui ne sautent pas des points fixes, une discontinuité de l'énergie libre pour un potentiel admettant des solutions qui inversent le sens du flot à température nulle et la non-existence de solutions à température finie associées à un flot entre minima pour un potentiel qui admet une telle solution à température nulle. / Over the past twenty years the idea that gravity is holographic has become progressively concrete, materialised through the AdS/CFT correspondence, also known as the gauge/gravity duality. CFT stands for conformal field theory and in the correspondence it is a gauge-theory in the large N limit1. AdS stands for anti-de Sitter space-time, a maximally symmetric solution of Einstein’s equations with negative cosmological constant, it corresponds to the gravitational side of the duality. In some limits, theories on AdS with gravity in d + 1 dimensions can be mapped to CFTs without gravity in d dimensions and vice-versa, hence the name “duality”. Another term for the gauge/gravity duality is holographic duality. The term holography comes from the Greek words holos, “whole”, and graphe, “writing” or “drawing”. In physics, the term holography originates in optics, referring to the possibility of generating a 3-dimensional image as a projection from a bi- dimensional screen or film. In such a projection, despite of the fact that the film has one spatial dimension less than the projection, the film would contain all the information to recover the three-dimensional image. In the gauge/gravity duality, the gauge-theory behaves as a d-dimensional film which contains the same information as the (d + 1)-dimensional gravitational image. This analogy is reinforced by the fact that the duality relates the gravitational theory to the dual resulting quantum field theory (QFT) via boundary conditions of the fields living in the AdS bulk. In this sense, the gauge theory can be thought of as living at the boundary of AdS and the duality is also know as the bulk/boundary correspondence. One of the most important features of the correspondence is the mapping of a strongly coupled QFT into a weakly coupled gravitational theory and vice-versa. For this reason, in this thesis I will use a weakly coupled bulk theory to explore and identify non-perturbative features of QFT in the strong coupling regime. This thesis explores holography at zero and finite temperature. Our main concern are the CFTs in which scale invariance is either spontaneously or explicitly broken and the resulting QFT can be studied via the renormalisation group (RG). The profile of fields along the extra-dimension in the bulk is dual to renormalisation group flows in the QFT side (boundary), as the extra-dimension can be mapped to an energy scale. The mapping goes further by identifying bulk fields as dual to QFT running couplings, leading to the so-called holographic renormalisation group. With the holographic RG in what follows I will explore behaviours that are of an intrinsically non-perturbative nature from the QFT standpoint. The main results are as follows. At zero temperature, for a single coupling, we classified all possible solutions in our setup and identified three kinds of exotic flows corresponding to solutions reversing direction along the flow (bounces), flows skipping fixed points and solutions interpolating between minima of the potential. These results are generalised to many couplings at zero temperature. I also present a complete map between forms of the Hamilton's principal function and the gradient or non-gradient nature of the solutions. At finite temperature we considered a single coupling setup and explored the thermodynamics of the three kinds of above-mentioned exotic flows. We identified a phase transition between skipping and non-skipping solutions, a discontinuous free energy for a bouncing potential and the non-existence of a finite-temperature solutions for a chosen potential admitting a minimum-to-minimum solution.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21559号 / 理博第4466号 / 新制||理||1641(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 川合 光, 教授 田中 貴浩, 教授 高柳 匡 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Wir untersuchen die perturbative Quantentheorie verschiedener integrabler Yang-Baxter-Deformationen des freien Superstrings auf AdS-Räumen. Dazu berechnen wir die Zwei-Körper-Streumatrix auf Baum-Niveau auf dem Weltenblatt mit Feynman-Diagramm-Methoden. Die verschiedenen Deformationen sind: (1) Alle abelschen Deformationen von AdS₅ ⨉ S⁵, die die Fixierung der Lichtkegel-Eichung erlauben. Diese sind dual zur nicht-kommutativen Super-Yang-Mills-Theorie und werden äquivalent durch TsT-Transformationen oder verwundene Randbedingungen beschrieben. Wir berechnen die bosonische Streumatrix auf Baum-Niveau für den BMN-String in uniformer Lichtkegel-Eichung. Die Streumatrix wird in den meisten Fällen durch einen Drinfeld-Verwindungen ausgedrückt; in einigen Fällen wird sie stattdessen durch eine verschobene Impulsabhängigkeit ausgedrückt. Abschließend vergleichen wir die aus diesen Ergebnissen abgeleiteten Bethe-Gleichungen mit denen des Modells mit verwundene Randbedingungen und stellen eine perfekte Übereinstimmung fest. Für Deformationen des GKP-Strings können wir aufgrund konzeptioneller Hindernisse keine deformierte Streumatrix um die Null-Cusp-Lösung bestimmen. (2) Die inhomogene oder eta-Deformation von AdS₅ ⨉ S⁵ entsprechend dem fermionischen Dynkin-Diagramm. Wir berechnen die Zwei-Körper-Streumatrix auf Baum-Niveau zu quadratischer fermionischer Ordnung in uniformer Lichtkegel-Eichung. Sie erfüllt die klassische Yang-Baxter-Gleichung, faktorisiert in zwei Blöcke und entspricht der exakten Streumatrix für ein Modell mit trigonometrisch quantendeformierter Symmetrie. (3) Inhomogene bi-Yang-Baxter-Deformationen von AdS₃ ⨉ S³ ⨉ T⁴ für mehrere Dynkin-Diagramme. Wir berechnen die Zwei-Körper-Streumatrix auf Baum-Niveau zu quadratischer fermionischer Ordnung in uniformer Lichtkegel-Eichung. Alle Deformationen ergeben die gleiche Streumatrix, die mit der erwarteten exakten Streumatrix bei trigonometrisch quantendeformierter Symmetrie übereinstimmt. / We study the perturbative quantum theory of various integrable Yang-Baxter deformations of the free superstring on AdS spaces. For this we compute the two-body tree-level scattering matrix on the worldsheet using Feynman diagram methods. The various deformations are: (1) All distinct Abelian deformations of AdS₅ ⨉ S⁵ allowing light-cone gauge fixing. These are dual to noncommutative super Yang-Mills theory and equivalently described through TsT transformations or twisted boundary conditions. We compute the bosonic tree-level scattering matrix for the BMN string in uniform light-cone gauge. The scattering matrix is expressed through a Drinfeld twist for most cases; for some cases it is expressed instead through a shifted momentum dependence. Lastly, we compare the Bethe equations derived from these results to the equations of the model with twisted boundary conditions and find perfect agreement. For deformations of the GKP string we are not able to determine a deformed scattering matrix around the null-cusp solution due to actions incompatible with perturbation theory in momentum space. (2) The inhomogeneous or eta deformation of AdS₅ ⨉ S⁵ corresponding to the fermionic Dynkin diagram. We compute the two-body tree-level scattering matrix up to second order in fermions in uniform light-cone gauge. It satisfies the classical Yang-Baxter equation, factorizes into two blocks and matches the exact scattering matrix for a model with trigonometrically quantum-deformed symmetry. (3) Inhomogeneous bi-Yang-Baxter deformations of AdS₃ ⨉ S³ ⨉ T⁴ for multiple Dynkin diagrams. We compute the two-body tree-level scattering matrix up to second order in fermions in uniform light-cone gauge. All deformations give the same scattering matrix, which matches the expected exact scattering matrix with trigonometrically quantum-deformed symmetry.

ADS-B är ett protokoll som används över hela världen för att piloter och flygledning ska få en bättre bild över trafiksituationen i luften.Tidigare studier har uppmärksammat att säkerheten kring protokollet är bristfällig eftersom det saknas kryptering. Det huvudsakliga sårbarheten som finns i protokollet beror på att autentisering saknas. Protokollet är alltså byggt på ett blint förtroende mellan sändare och mottagare.Vårt arbete är inspirerat av tidigare forskning som gjorts inom området som bland annat visar att det går att skapa s.k. “spökflygplan” genom att sända falsk data över protokollet. Syftet bakom denna rapport var att utföra ett penetrationstest på en populär ADS-B produkt riktad mot piloter. Våra tester bygger på OSSTMM3, en vetenskaplig metod för att testa säkerhet.Våra tester visar att mottagaren som testade, inte helt oväntat, följer protokollet utan att validera data. Vi lyckades precis som tidigare forskare injicera statiska spökflygplan men också manipulera rörelsen av ett spökflygplan på ett sätt som strider mot fysikens rörelselagar. Våra tester visar att tjänsten som levereras av mottagaren kan störas ut genom att utföra liknande attacker. / The ADS-B protocol is currently in use all around the world. The purpose behind the protocol is to give pilots and traffic control a better picture of the situation in the air. Previous research shows that there exists a vulnerability in the protocol since it lacks authentication. The protocol is solely built upon trust between sender and receiver.Our work is inspired by previous studies made in the area, where it has been demonstrated that one can inject fake aircraft by sending fake ADS-B data using the protocol. The purpose behind this report was to perform a penetration test according to the OSSTMM3, a manual on how to perform scientific penetration tests.We wanted to test a real product (ADS-B receiver) made for pilots and measure if we could manipulate the environment presented to the pilot.Our testing shows that the receiver blindly trusts the protocol without any data validation. We managed to inject fake static aircraft just like previous researchers have done, but also move them around in the environment in a way that breaks the laws of physics and flood the device with fake data, effectively denying the service provided.Since we managed to deny the service, which is to give the user a correct picture of the nearby air traffic, we feel like our tests were successful.

The thesis is focused on most recent trends in the mobile marketing industry, paid mobile advertising market structure, size and processes. The aim of the thesis is to define the possibilities of using mobile advertising in two basic segments mobile advertising in search and mobile display advertising. It provides performance results of the paid mobile advertising campaigns and their role in the corporate practice. The last part provides in-depth view about use of mobile advertising at the company AVG Technologies. It illustrates how the company increased the number of app installations and factors that influence the effectiveness of in-app advertising campaigns in general.

Background and problem discussion Organizations are today facing an uncertainty regarding how to properly integrate and work with CRM, in particular in regards to attraction and retention of customers. This can be managed through the use of marketing campaigns. There is a lack of practical research regarding the management and how to optimize the budget of marketing campaigns. Purpose The purpose of this study is to develop a deeper understanding of how small e-commerce retailers within the beauty industry can optimize the marketing budget for social media campaigns. The purpose will be realized through application of hypotheses. Method This study has applied an experimental method design, where cause-effect in regards to how the marketing communication has influenced the customer behavior was investigated. This has been made through applying a modified A/B-test through the use of a marketing campaign, containing of three ads. The ads have been adapted in regards to the pre-study, using a company’s historical transaction data. Conclusion The results of the A/B-test show higher effectiveness and efficiency in the form of CTR, CPC,CPM, link klicks, more purchases, and lower cost per result. This is the result of the adaptation of the ads in regards to the target group. All of the ads in the campaign display a higher value than the Swedish average. This validates the notion that ads adjustments have a positive effect on customer conversion, and as a result on optimizing social media campaigns marketing budget. / Bakgrund och problemdiskussion Det råder osäkerhet hos företag hur de ska integrera och arbeta med CRM, i synnerlighet om attraherandet samt bibehållandet av kunder. Detta är något som företag kan hantera genomkampanjer, dock finns det en brist på praktisk forskning runt hantering och effektivisering av kampanjer och dess marknadsföringsbudget. Syfte Syftet med studien är att skapa en djupare förståelse för hur små e-handelsåterförsäljare inom skönhetsbranschen kan optimera en marknadsföringsbudget vid kampanjer på sociala medier. Syftet kommer att uppfyllas med en rad hypoteser. Metod Studien har designats som ett experiment då orsak-verkan undersöktes i hur kunders beteende påverkas av anpassad marknadskommunikation. Detta har gjorts genom att utforma ett modifierat A/B-test i form av en kampanj innehållandes tre annonser, vilket anpassats utifrån en förstudiebaserat på ett företags tidigare transaktionsdata. Slutsats Resultat av A/B-testet påvisar en höjd effektivitet i form av CTR, CPC, CPM, länkklick, flergenomförda köp samt ett lägre kostnad per resultat, detta till följd av annonsens anpassning till en specifik målgrupp. Samtliga annonserna i kampanjen visar på högre värden än det svenskagenomsnittet. Detta resultat visar på att anpassade annonser har en positiv påverkan på kundkonvertering, och därigenom på optimeringen av marknadsföringsbudgeten för sociala medier.

La loi française du 28 juin 2006, sur la gestion des déchets radioactifs, demande une évaluation pour définir la future stratégie industrielle. L’étude présentée ici, concerne plus spécifiquement l’axe de recherche sur la transmutation des actinides mineurs. Dans ce but, un concept d’ADS (Accelerator DrivenSystem) de haute puissance a été développé à SUBATECH. Dans ce réacteur sous-critique, un faisceau de protons de 1 GeV alimente trois cibles de spallation de plomb-bismuth. L’ADS MUST (MUltipleSpallation Target) peut ainsi atteindre une puissance thermique de plus de 1 GW avec une densité de puissance élevée. Une méthode de dimensionnement de ces réacteurs a été développée et appliquée pour différents scénarios double strate. Dans ces scénarios, des réacteurs électrogènes de type SFR (Sodium Fast Reactors) ou REP (Réacteurs à Eau Pressurisée) produisent des actinides mineurs destinés à être transmutés en ADS. Dans chaque cœur, un multi-recyclage du plutonium est réalisé et dans les réacteurs sous-critiques les éléments à transmuter le sont également. Pour limiter la réactivité du cœur et améliorer la conductivité thermique, le combustible contenant les actinides mineurs est mélangé à une matrice inerte de MgO. Des filières, avec des ADS à caloporteurs plomb et sodium, ont été étudiées pour différentes durées d’irradiation, et deux stratégies de transmutation : soit l’ensemble des actinides mineurs, soit seulement l’américium est incinéré. Le dimensionnement des ADS MUST de chaque filière et de leur combustible à l’équilibre est présenté dans cette thèse. Puis l’évolution du combustible et du coefficient de multiplication, sur un cycle, est réalisée et analysée. La radiotoxicité et la puissance thermique des déchets produits sont ensuite comparées. Enfin, l’étude de scénarios double strate est effectué afin d’analyser les inventaires d’actinides mineurs et de plutonium en cycle, ainsi que les déchets produits en fonction de la stratégie de transmutation adoptées et de l’évolution de la première strate. / The French law of 28th June 2006 regarding advanced nuclear waste management requires a scientific assessment to define future industrial strategies. The present PhD thesis was carried in this framework and concerns specifically the research axis of minoractinides transmutation. A high power Accelerator Driven System (ADS) concept is developed at SUBATECH for this purpose. A 1 GeV proton beam feeds three liquid lead-bismuth spallation targets. The MUltiple Spallation Target (MUST) ADS reaches the thermal powers up to 1 GW with a high specific power. A nuclear reactor dimensioning method has been developed and applied to different double strata scenarios. In these scenarios, SFR (Sodium FastReactors) or PWR (Pressurized Water Reactors) power reactors produce minor actinides that will be transmuted into ADS. In each core (SFR and ADS), the plutonium multi-reprocessing strategy is performed while ADS subcritical core also multi-reprocesses minor actinides. To limit the core reactivity and improve the fuel thermal conductivity, the minor actinides fuel is mixed with MgO inert matrix. Nuclear branches with lead and sodium coolants for the ADS, have been studied for different irradiation times and two transmutation strategies have been assessed : whether whole minor actinides, whether americium only is tranmuted. The thesis presents precisely the MUST ADS design methodology and the calculations to get a fuel composition at equilibrium. Then a one cycle evolution is performed and analysed for the fuel and the multiplication factor. Radiotoxicity and thermal power of the waste produced are then compared. Finally, the study of double strata scenarios is performed to analyse the plutonium and minor actinides inventories in cycle and also the waste produced according to the transmutation strategies applied and the first stratum evolution.

Devido ao alto número de propagandas que um consumidor é exposto em um único dia, torna-se fundamental que as empresas produzam anúncios que atinjam de forma efetiva seu público-alvo. Um anúncio precisa chamar a atenção de uma pessoa e, ainda, impactar em suas atitudes. Ressalta-se que fatores como gênero e nível de envolvimento do consumidor são variáveis que impactam na atenção dedicada a um anúncio e nas ações posteriores a este. Ainda, a forma como o anúncio é elaborado, ou seja, o tipo de anúncio, pode interferir nas reações dos consumidores. Este estudo teve por objetivo identificar como diferentes tipos de anúncio, sejam estes direcionados ao público masculino, feminino ou neutros impactam na atenção visual e nas atitudes em relação a estes anúncios e, também, como o gênero e o nível de envolvimento influenciam nessa relação. Através de um pré-teste, foram selecionadas seis imagens para compor o estudo. Através de um experimento, os participantes foram divididos em três grupos e submetidos a visualização de um dos tipos de anúncio escolhido. A coleta de dados foi dada por meio do eye-tracking e de questionários e os dados foram analisados por meio da análise fatorial, testes de hipótese e complementados com estatística descritiva. Foi identificado que o tipo de anúncio impacta na atenção visual e nas atitudes em relação ao anúncio. Em relação às variáveis moderadoras do estudo, foi visto que o gênero impacta apenas nas respostas dos anúncios considerados masculinos e que, de forma mais evidente, o nível de envolvimento impacta nas respostas dos anúncios, principalmente nas atitudes em relação ao anúncio / Due to the high number of advertisements that a consumer is exposed in a single day, it is critical that companies produce ads that effectively reach their target audience. An ad needs to catch a person\'s attention and still impact their attitudes. It should be noted that factors such as gender and level of consumer involvement are variables that impact on the attention devoted to an ad and on the actions subsequent to it. Yet, the way the ad is designed, that is, the type of ad, can interfere with consumer reactions. The purpose of this study was to identify how different types of advertisements, whether directed at the male, female or neutral public, impact on visual attention and attitudes towards these ads, and how gender and level of involvement influence this relationship. Through a pre-test, six images were selected to compose the study. Then, through an experiment, the participants were divided into three groups and submitted to the visualization of one of the chosen ad types. Data were collected through eye-tracking and questionnaires and the data were analyzed through factorial analysis, hypothesis tests and complemented with descriptive statistics. It has been identified that the type of ad impacts on visual attention and attitudes toward the ad. Regarding the moderating variables of the study, it was seen that the gender impacts only on the responses of the ads considered masculine and that, more clearly, the level of involvement impacts on the responses of the ads, mainly in the attitudes towards the advertisement

This thesis consists in a self-contained study of gauge/gravity dualities in the line of the Klebanov-Witten model. Here we explore first the known Maldacena duality that relates N=4 SYM theory in four dimensions to type IIB supergravity on AdS_5×S^5 in reasonable detail, after some necessary preliminaries on supersymmetric gauge theories, where we display in detail the supersymmetry algebra and representations for N 1 supersymmetry. There we also construct the so-called superfields that will be helpful to write invariant lagrangians for gauge theoriesmreadily, and then useful to construct the gauge theory side of the Klebanov-Witten model. In the original AdS/CFT correspondence and its phenomenologically interesting extensions, Dp-branes as solutions of supergravity and nonperturbative objects in string theory where gauge theory lives are crucial. So, to preserve the self-contained nature of this work, we include a brief review of superstring theory addressed to understand the need to include this higher-dimensional objects by T-duality and, at low-energy limit of the string theory, as solutions of the Einstein equations. The first climax of this work occurs when we use all we learned to establish the Maldacena conjecture, N=4 SU(Nc) SYM theory we study in the supersymmetry chapter, living on the four-dimensional worldvolume of a stack of Nc D3-branes in a flat-space, corresponds exactly to type IIB supergravity on AdS_5×S^5 .In order to prove it, we match symmetries and operators with states in both sides. But actually this corresponds to the weak form of the correspondence, because it is not possible to handle neither string theory or gauge theory at strong coupling. The focus and main motive to have to learn the first hundred of pages here will be to extend the dual gauge theory we studied in AdS/CFT towards more realistic gauge theories as duals of some supergravity theory. The Klebanov-Witten model, consists in replacing the five-sphere in the gravity background of type IIB for a more interesting Einstein manifold X5 , a coset space called T^1,1 .The resulting dual gauge theory is expected to be less supersymmetric, and it is indeed N = 1 superconformal field theory with matter content in the bifundamental representation of the gauge group SU(N)×SU(N), and a quartic superpotential that exhibits SU(2)×SU(2)×U(1) global symmetry, which is precisely the symmetry of the coset space in the gravity side. This is not the end of the story, the Klebanov-Witten model extended the Maldacena correspondence and found as a dual gauge theory a less supersymmetric but still conformal theory. Breaking of the conformal theory, proposed by Klebanov, Nekrasov and Tseytlin, is achieved by introducing fractional M D3-branes in addition to the N regular D3-branes. The resulting theory is an SU(N+M)×SU(N) gauge theory with N = 1 supersymmetry, no longer conformal and then a little more interesting as a part of the crusade to find a QCD-like theory. This is still not the end, the last model suffers from a singularity in the deep IR, rendering the gravitational description invalid in that regime. It was conjectured that the strong dynamics of the gauge theory should somehow resolve this problem. Klebanov, again, and Strassler showed that this conjecture was correct, and argue that the RG flow is in fact an infinite series of Seiberg duality transformations- a cascade - in which the number of colors repeatedly drops from N NM , so the gaugegroup changes from SU(N+M)×SU(N) to SU(NM) ×SU(N). This process can be repeated until the IR limit where the gauge group simply becomes SU(M). So, at the end we get a N=1 SU(M) gauge theory, a QCD-like theory. We say that the standard model itself may lie at the base of a duality cascade. / Essa tese consiste num estudo autocontido das dualidades calibre/gravidade na linha do modelo do Klebanov-Witten. Aqui nos exploramos primeiro de um jeito razoavelmente detalhado,a conhecida dualidade do Maldacena que relaciona a teoria N=4 SYM em quatro dimensões com as supercordas tipo IIB no espaço AdS_5×S^5, depois de alguns preliminares necessários sobre teorias supersimétricas de calibre, onde nós mostramos em detalhe à algebra supersimétrica e as representações para N 1 supersimetria. Nós também construímos os conhecidos supercampos que são úteis para escrever lagrangianas invariantes para teorias de calibre facilmente, e então serão úteis para construir a teoría de calibre do modelo de Klebanov-Witten. Na correspondência AdS/CFT original e as suas extensões fenomenologicamente interessantes, as Dp-branas, como soluções de supergravidade e objetos não perturbativos na teoria de cordas onde as teorias de calibre moram, são essenciais. Assim ,a fim de preservar a natureza autocontida desse trabalho, nós incluímos uma breve revisão sobre teoria de supercordas dirigida a entender a necessidade de incluir esses objetos extra-dimensionais usando dualidade-T e, no limite de baixa-energia da teoria de cordas, como soluções das equações de Einstein. O primeiro clímax desse trabalho ocorre quando nós usamos tudo o que aprendemos para estabelecer a conjectura do Maldacena, a teoria de calibre N=4 SYM que nós estudamos no capítulo de supersimetria, morando no volume de mundo quadridimensional de uma pilha de Nc D3-branas (sim, o subscrito c significa cor!) em espaço plano, corresponde exatamente à teoria de supergravidade tipo IIB no espaço AdS_5×S^5 . A fim de testar ela, nós identificamos simetrias e operadores com estados em ambos lados da dualidade. Mas na verdade isto corresponde à forma fraca da correspondência, porque não é possível lidar nem com a teoria de cordas nem com a teoria de calibre no limite de acoplamento forte. O foco e motivo principal de porque nós temos que aprender as primeiras cem páginas aqui, será estender a teoria de calibre dual que estudamos em AdS/CFT, para teorias de calibre mais realisticas como duais de alguma teoria de supergravidade. O modelo do Klebanov-Witten, consiste em substituir a esfera de cinco dimensões no fundo de supergravidade da teoria de supercordas tipo IIB por um espaço que é mais interessante X5, um espaço coset chamado T^1,1. Nós esperamos que a teoria de calibre dual que resulta é menos supersimetrica, e na verdade é N =1 superconforme com um conteúdo de matéria na representação bifundamental do grupo de calibre SU(N)×SU(N), e um superpotencial quártico que tem simetria global SU(2)×SU(2)×U(1), que é precisamente a simetria do espaço coset no lado da gravidade. Mas isso não é tudo, o modelo do Klebanov-Witten estendeu a correspondência do Maldacena e encontrou como teoria dual uma teoria menos supersimetrica mas ainda conforme. A quebra da simetria conforme, proposta pelo Klebanov, Nekrasov e Tseytlin, é obtida introduzindo M D3-branas fracionais além das N D3-branas regulares. A teoria resultante é uma teoria de calibre SU(N+M)×SU(N) com N = 1 supersimetria, não mais conforme e então um pouco mais interessante como parte da nossa cruzada para encontrar uma teoria tipo-QCD. Isso ainda não é o final, o modelo anterior sofre de uma singularidade no IR profundo, tornando inválido a descrição gravitacional. Foi conjeturado então que a dinâmica do acoplamento forte na teoria de gauge deveria de algum jeito resolver esse problema. Klebanov, de novo, e Strassler mostraram que essa conjetura foi correta, e argumentaram que o fluxo do GR é de fato uma serie infinita de transformações de dualidade de Seiberg - uma cascata - onde o numero de cores cai repetidamente de NNM, e o grupo de calibre muda de SU(N+M)×SU(N) a SU(NM)×SU(N). O processo pode ser repetido até o limite IV onde o grupo de calibre simplesmente torna-se SU(M). Então, no final nós obtemos uma N = 1 teoria de calibre SU (M ), ou seja uma teoria tipo-QCD. Então, nós dissemos que o modelo padrão mesmo pode se situar na base da cascata de dualidade.