Дисертації: "Gauge Theory, Supergravity, Supersymmetry"

1

Brandhuber, A., K. Sfetsos, and brandhu@mail cern ch. "An N=2 Gauge Theory and its Supergravity Dual." ESI preprints, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi898.ps.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Gregory, Carolina Matté. "Supergravity duals to five-dimensional supersymmetric gauge theories." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:035f080b-1726-4953-bdf8-89cea2215572.

Повний текст джерела

Анотація:

In this thesis we study gauge/gravity duals in the 5d/6d AdS/CFT correspondence. We start with field theories defined on squashed five-spheres with SU(3) × U(1) symmetry. These five-sphere backgrounds are continuously connected to the round sphere. We find a one-parameter family of 3/4 BPS deformations and a two-parameter family of (generically) 1/4 BPS deformations. The gravity duals are constructed in Euclidean Romans F(4) gauged supergravity in six dimensions, and uplift to massive type IIA supergravity. We holographically renormalize the Romans theory, and use our general result to compute the renormalized on-shell actions for the solutions. The results agree perfectly with the large N limit of the dual gauge theory partition function, which we compute using large N matrix model techniques. In addition we compute BPS Wilson loops in these backgrounds, both in supergravity and in the large N matrix model, again finding precise agreement. We conjecture a general formula for the partition function on any five-sphere background, which for fixed gauge theory depends only on a certain supersymmetric Killing vector. We then proceed to study Euclidean Romans supergravity in six dimensions with a non-trivial Abelian R-symmetry gauge field. We show that supersymmetric solutions are in one-to-one correspondence with solutions to a set of differential constraints on an SU(2) structure. As an application of our results we (i) show that this structure reduces at a conformal boundary to the five-dimensional rigid supersymmetric geometry previously studied, (ii) find a general expression for the holographic dual of the VEV of a BPS Wilson loop, matching an exact field theory computation, (iii) construct holographic duals to squashed Sasaki-Einstein backgrounds, again matching to a field theory computation, and (iv) find new analytic solutions to the squashed five-sphere background. We also analyse the classification of gravity duals with zero B-field.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Ouvry, Stéphane. "Naturalité des théories de jauge (grand-)unifiées et de la supergravité." Paris 6, 1986. http://www.theses.fr/1986PA066423.

Повний текст джерела

Анотація:

Rappels sur la naturalité. Exemple dans le cas de la symétrie de Peccei-Quinn dans les modèles de grande unification ainsi que d'autres difficultés liées à son existence. On propose une solution techniquement naturelle au problème de la violation de CP par les interactions fortes: la symétrie p. Q. Est automatiquement et explicitement brisée au niveau classique, mais doucement. Pour une nouvelle classe de modèles de la super gravité n=1, on étudie la rupture spontanée de la supersymétrie locale avec une constante cosmologique nulle. Cette classe de modèles correspond dans le superespace à la super gravité de Wess et Zumino, dérivée par la substitution minimale des opérateurs globalement supersymétriques. On donne des résultats sur la gravité superconforme n=1 et la réductibilité de la supergravité n=1 "16+16

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Clark, Adam Benjamin. "Applications of conformal perturbation theory to novel geometries in the gauge/gravity correspondence /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/9789.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Katona, Gregory. "Field Theoretic Lagrangian From Off-Shell Supermultiplet Gauge Quotients." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5958.

Повний текст джерела

Анотація:

Recent efforts to classify off-shell representations of supersymmetry without a central charge have focused upon directed, supermultiplet graphs of hypercubic topology known as Adinkras. These encodings of Super Poincare algebras, depict every generator of a chosen supersymmetry as a node-pair transformtion between fermionic / bosonic component fields. This research thesis is a culmination of investigating novel diagrammatic sums of gauge quotients by supersymmetric images of other Adinkras, and the correlated building of field theoretic worldline Lagrangians to accommodate both classical and quantum venues. We find Ref [40], that such gauge quotients do not yield other stand alone or ”proper” Adinkras as afore sighted, nor can they be decomposed into supermultiplet sums, but are rather a connected ”Adinkraic network”. Their iteration, analogous to Weyl's construction for producing all finite-dimensional unitary representations in Lie algebras, sets off chains of algebraic paradigms in discrete-graph and continuous-field variables, the links of which feature distinct, supersymmetric Lagrangian templates. Collectively, these Adiankraic series air new symbolic genera for equation to phase moments in Feynman path integrals. Guided in this light, we proceed by constructing Lagrangians actions for the N = 3 supermultiplet YI /(iDI X) for I = 1, 2, 3, where YI and X are standard, Salam-Strathdee superfields: YI fermionic and X bosonic. The system, bilinear in the component fields exhibits a total of thirteen free parameters, seven of which specify Zeeman-like coupling to external background (magnetic) fluxes. All but special subsets of this parameter space describe aperiodic oscillatory responses, some of which are found to be surprisingly controlled by the golden ratio, ? ? 1.61803, Ref [52]. It is further determined that these Lagrangians allow an N = 3 ? 4 supersymmetric extension to the Chiral-Chiral and Chiral-twisted- Chiral multiplet, while a subset admits two inequivalent such extensions. In a natural progression, a continuum of observably and usefully inequivalent, finite-dimensional off-shell representations of worldline N = 4 extended supersymmetry are explored, that are variate from one another but in the value of a tuning parameter, Ref [53]. Their dynamics turns out to be nontrivial already when restricting to just bilinear Lagrangians. In particular, we find a 34-parameter family of bilinear Lagrangians that couple two differently tuned supermultiplets to each other and to external magnetic fluxes, where the explicit parameter dependence is unremovable by any field redefinition and is therefore observable. This offers the evaluation of X-phase sensitive, off-shell path integrals with promising correlations to group product decompositions and to deriving source emergences of higher-order background flux-forms on 2-dimensional manifolds, the stacks of which comprise space-time volumes. Application to nonlinear sigma models would naturally follow, having potential use in M- and F- string theories.
Ph.D.
Doctorate
Physics
Sciences
Physics

Стилі APA, Harvard, Vancouver, ISO та ін.

6

De, Notariis Kevin. "Light hyperweak new gauge bosons from kinetic mixing in string models." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19491/.

Повний текст джерела

Анотація:

String theory is at the moment our best candidate for a unified quantum theory of gravity, aiming to reconcile all the known (and unknown) interactions with gravity as well as provide insights for currently mysterious phenomena that the Standard Model and the modern Cosmology are not able to explain. In fact, it is believed that most of the problems associated to the Standard Model can indeed be resolved in string theory. Supersymmetry is supposed to be an elegant solution to the Hierarchy problem (even though more and more stringent bounds in this direction are being placed by the fact that we have been unable to experimentally find supersymmetry yet), while all the axions that compactifications bring into play can be used to resolve the strong CP problem as well as provide good candidates for Dark Matter. Inflationary models can also be constructed in string theory, providing, then, the most diffused solution to the Horizon problem. This work, in particular, is formulated in type IIB string theory compactified on an orientifolded Calabi-Yau three-fold in LARGE Volume Scenario (LVS) and focuses on the stabilisation of all the moduli in play compatible with the construction of a hidden gauge sector whose gauge boson kinetically mixes to the visible sector U(1), acquiring a mass via a completely stringy process resulting in the St{\"u}ckelberg mechanism. The "compatibility" regards the fact that certain experimental bounds should be respected combined with recent data extrapolated by Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) events at the Spallation Neutron Source at Oak Ridge National Laboratory. We are going to see that in this context we will be able to fix all the moduli as well as present a brane and fluxes set-up reproducing the correct mass and coupling of the hidden gauge boson. We also get a TeV scale supersymmetry, since the gravitino in this model will be of order O(TeV), with an uplifted vacuum to reproduce a de Sitter universe as well.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Petri, N. "SUPERSYMMETRIC OBJECTS IN GAUGED SUPERGRAVITIES." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/545103.

Повний текст джерела

Анотація:

The formulation of a unified description of fundamental interactions has always been the most relevant and intriguing challenge in physics. To this end, a microscopic description of gravity and its consequent unification to electromagnetic and nuclear forces is needed. A theory realizing such a framework would be called theory of quantum gravity and, so far, the only consistent setup which seeks to realize this purpose is given by string theory. In this context, the divergences appearing in classical gravity theory are resolved at high energies in terms of contributions coming from the physics of extra dimensions. From this point of view, in order to gain the stability of higher-dimensional objects, like strings and branes, the formulation of quantum theories of gravity requires supersymmetry. These fundamental extended objects give rise, at low energies, to supersymmetric systems that are strongly coupled to gravity like, for example, black holes. The theories describing the low-energy regime of objects living at higher dimensions are called supergravity theories and constitute the general setup of this thesis. These are classical interacting theories of gravity characterized by local supersymmetry. In this context, the description of supersymmetric objects is realized by classical solutions of the equations of motion and the link with high energies is controlled by the AdS/CFT correspondence and by string compactifications. Starting from this general framework, in this thesis the results published during the three years of doctoral studies are presented. Three particular supergravity realizations in four- five- and seven dimensions are considered and discussed in relation to the physics of the supersymmetric objects arising from them. The analysis of the results in terms of the underlying microscopic theories is also developed with particular emphasis on string compactifications, giving rise to the three supergravities considered, and on the holographic interpretation, explaining the origin of the supersymmetric solutions presented in terms of non-perturbative states of string theory.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Kraj, Megan C. "Supersymmetry, supergravity, and String Theory based inflationary cosmology." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127088.

Повний текст джерела

Анотація:

Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 150-151).
The aim of this thesis is to investigate and present an overview of inflationary theory. As part of this effort, the main motivations for cosmic inflation, which are known as problems in the standard big bang scenario, are reviewed. These problems are the "flatness problem", "horizon problem", and the "monopole problem." Analysis of inflation caused by a single scalar field rolling on a scalar potential is considered. This enables the introduction of the "slow-roll parameters" and their application. Since supersymmetry is considered a candidate beyond the standard model theory, we explore the connection between supersymmetry and the early universe. In order to incorporate gravity at energy scales of the early universe, supergravity is examined as well. Having considered inflation in the context of supersymmetry and supergravity, it is therefore natural to present the role of string theory in inflationary model building. As a result, axion monodromy is considered. Representative models are compared to analysis of precision measurements of the cosmic microwave background radiation. This comparison is achieved using observable derived constraints of the spectral index and tensor to scalar ratio.
by Megan C. Kralj.
S.B.
S.B. Massachusetts Institute of Technology, Department of Physics

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Hustler, Noel. "Homogeneity in supergravity." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/19576.

Повний текст джерела

Анотація:

This thesis is divided into three main parts. In the first of these (comprising chapters 1 and 2) we present the physical context of the research and cover the basic geometric background we will need to use throughout the rest of this thesis. In the second part (comprising chapters 3 to 5) we motivate and develop the strong homogeneity theorem for supergravity backgrounds. We go on to prove it directly for a number of top-dimensional Poincaré supergravities and furthermore demonstrate how it also generically applies to dimensional reductions of those theories. In the third part (comprising chapters 6 and 7) we show how further specialising to the case of symmetric backgrounds allows us to compute complete classifications of such backgrounds. We demonstrate this by classifying all symmetric type IIB supergravity backgrounds. Next we apply an algorithm for computing the supersymmetry of symmetric backgrounds and use this to classify all supersymmetric symmetric M-theory backgrounds.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Le, Diffon Arnaud. "Supergravités jaugées et symétrie locale d'échelle." Lyon, Ecole normale supérieure, 2010. http://www.theses.fr/2010ENSL0570.

Повний текст джерела

Анотація:

To address the problem of the unification of the four fundamental interactions, numerous works have been proposed. String theory could be a good answer. Compared to quantum field theory (QFT), describing annihilation and creation of point-particles, string theory describes the dynamics of one-dimensional strings. It has also been found that local supersymmetric field theories, known as supergravities, are low-energy limit of string theories. The use of supersymmetry, which relates bosons and fermions in the same framework, improves the quantum behaviour of field theories, and is necessary to string theory for mathematical consistency reasons. The edification of the standard model of particle physics is based on QFTs with non-abelian gauge symmetries, known as Yang- Mills theories. In the perspective of the unification of the four interactions, supergravities with nonabelian gauge interactions are relevant effective field theories. Using a systematic method to generate non-abelian gauged supergravities, this thesis completes the classification of gauged supergravities by including a local scaling symmetry. The formalism of the embedding tensor is used to build a local gauge group from the global symmetries of supergravity theory. These particular theories including a local scaling symmetry are submitted to new constraints and they do no longer possess an action. Consequently, we are led to build the gauged theory at the level of the equations of motion. An interesting consequence of gauged supergravities with local scaling symmetry is the presence of a positive contribution to the scalar potential in Einstein equations, which could lead to de Sitter vacuum solutions
Pour répondre au problème de l'unification des interactions fondamentales, de nombreux travaux ont été proposés, et parmi eux la théorie des cordes. La théorie quantique des champs décrit les annihilations et créations de particules ponctuelles. En revanche, la théorie des cordes décrit la dynamique d'objets unidimensionnels. De plus, les théories des champs présentant unesupersymétrie locale (supergravités) sont des limites de basse énergie de théories de cordes. La supersymétrie, reliant bosons et fermions, améliore considérablement le comportement quantique des théories de champs, et demeure un élément essentiel de la théorie des cordes. La construction du modèle standard de la physique des particules fait appel à la théorie quantique des champs en présence de symétries de jauge non-abéliennes de type Yang-Mills. Dans la perspective d'unifier les interactions, la supergravité en présence de symétries de jauge non abélienne est une théorie effective pertinente. Dans cette thèse, nous complétons la classification des théories de supergravités jaugées en présence d'une symétrie locale d'échelle. Le formalisme de « l'Embedding Tensor » nous permet de construire un groupe de jauge local à partir des symétries globales de la supergravité. Ces théories particulières incluant une symétrie locale d'échelle sont soumises à des contraintes supplémentaires et modifiées, et ne possèdent plus d'action. Par conséquent, nous sommes contraints de travailler avec les équations du mouvement de la théorie. Une conséquence intéressante de ces théories est une contribution positive au potentiel scalaire dans les équations d'Einstein, ce qui serait le signe de solutions de Sitter

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Baguet, Arnaud. "Exceptional Field Theory and Supergravity." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN022/document.

Повний текст джерела

Анотація:

Dans cette thèse, nous présentons des avancements récents en Théorie des Champs Doubles (TCD) et Théories des Champs Exceptionnels (TCE). Ces théories ont la particularité d’être des reformulations de supergravité dans lesquelles les symétries de dualité sont explicites avant toute réduction dimensionnelle. Ces reformulations se basent sur la définition d’un espace-temps étendu qui géométrise le groupe de T-dualité en TCD et les groupes exceptionnels de U-dualité en TCE. Tous les champs de cet espace sont soumis à une contrainte de section qui restreint leur dépendance en coordonnées. Il existe plusieurs solutions à la contrainte de section, qui correspondent donc à des théories différentes. Dans ce sens, le formalisme des théories des champs étendues amène à une unification de ces théories. De plus, grâce à un outil spécifique aux théories des champs étendues, l’ansatz de Scherk-Schwarz généralisé, il est possible de réécrire les ansatz compliqué de type Kaluza-Klein en supergravité sous une forme élégante et compacte: un produit matriciel en dimensions supérieures. Ici, nous présentons plusieurs exemples de l’efficacité de l’ansatz de Scherk-Schwarz généralisé. En particulier, nous prouvons deux conjectures concernant les troncations cohérentes: la réduction dite “de Pauli” de la corde bosonique ainsi que la supergravité de type IIB sur AdS5 x S5. La dernière application de cet ansatz concerne la théorie de type IIB généralisée, apparue récemment dans l’étude des système intégrables, et son plongement dans la TCE E6(6). Enfin, nous présentons la complétion supersymétrique de la TCE E8(8) bosonique
In this thesis, recent developments in Double Field Theory (DFT) and Exceptional Field Theory (EFT) are presented. They are reformulation of supergravity in which duality symmetries are made manifest before dimensional reduction. This is achieved through the definition of an extended spacetime that “geometrises” the T-duality group O(d,d) in DFT and exceptional U-duality groups in EFT. All functions on this extended space are subject to a covariant `section constraint', whose solutions then restrict the coordinates dependency of the fields. There exist different solutions to the section constraint that correspond to different theories. In this sense, different theories are unified within the formalism of extended field theories. Moreover, extended field theories possess a powerful tool to study compactifications: the generalised Scherk-Schwarz ansatz.Here, we present several examples of the effectiveness of the generalised Scherk-Schwarz ansatz. In particular, we proved two conjectures regarding consistent truncations: the so-called Pauli reduction of the bosonic string on group manifolds and type IIB supergravity on AdS5 x S5. Another application is presented on the embedding of generalised type IIB within the E6(6) EFT, which recently appeared in the study of integrable systems.Finally, we present the supersymmetric completion of the bosonic E8(8) EFT

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Lee, Hok Kong Schwarz John H. "Gauge theory and supergravity duality in the pp-wave background /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-05262005-151056.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Schmidt, Torsten. "Supersymmetry, quantum gauge anomalies and generalized Chern-Simons terms in chiral gauge theory." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-101407.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Jia, Bei. "Aspects of Supersymmetry." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47495.

Повний текст джерела

Анотація:

This thesis is devoted to a discussion of various aspects of supersymmetric quantum field theories in four and two dimensions. In four dimensions, 𝒩 = 1 supersymmetric quantum gauge theories on various four-manifolds are constructed. Many of their properties, some of which are distinct to the theories on flat spacetime, are analyzed. In two dimensions, general 𝒩 = (2, 2) nonlinear sigma models on S² are constructed, both for chiral multiplets and twisted chiral multiplets. The explicit curvature coupling terms and their effects are discussed. Finally, 𝒩 = (0, 2) gauged linear sigma models with nonabelian gauge groups are analyzed. In particular, various dualities between these nonabelian gauge theories are discussed in a geometric content, based on their Higgs branch structure.
Ph. D.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Hama, Naofumi. "The localization calculation on supersymmetric gauge theories and its application." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215311.

Повний текст джерела

Анотація:

On open access repositories Creative Commons Attribution License CC-BY 4.0 Published source must be acknowledged Publisher's version/PDF may be used
Kyoto University (京都大学)
0048
新制・課程博士
博士(理学)
甲第19498号
理博第4158号
新制||理||1597(附属図書館)
32534
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)准教授國友浩, 教授田中貴浩, 教授杉本茂樹
学位規則第4条第1項該当

Стилі APA, Harvard, Vancouver, ISO та ін.

16

McCarthy, Shane A. "Topics in nonlinear self-dual supersymmetric theories." University of Western Australia. School of Physics, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0045.

Повний текст джерела

Анотація:

[Truncated abstract. Formulae and special characters can only be approximated. See PDF version for accurate reproduction.] Theories of self-dual supersymmetric nonlinear electrodynamics are generalized to a curved superspace of 4D N = 1 supergravity, for both the old-minimal and the newminimal versions of N = 1 supergravity. We derive the self-duality equation, which has to be satisfied by the action functional of any U(1) duality invariant model of a massless vector multiplet, and show that such models are invariant under a superfield Legendre transformation. We construct a family of self-dual nonlinear models, which includes a minimal curved superspace extension of the N = 1 supersymmetric Born- Infeld action. The supercurrent and supertrace of such models are explicitly derived and proved to be duality invariant. The requirement of nonlinear self-duality turns out to yield nontrivial couplings of the vector multiplet to Kähler sigma models. We explicitly construct such couplings in the case when the matter chiral multiplets are inert under the duality rotations, and more specifically to the dilaton-axion chiral multiplet when the group of duality rotations is enhanced to SL(2,R). The component structure of the nonlinear dynamical systems introduced proves to be more complicated, especially in the presence of supergravity, as compared with well-studied effective supersymmetric theories containing at most two derivatives (including nonlinear Kähler sigma-models). As a result, when deriving their canonically normalized component actions, the traditional approach becomes impractical and cumbersome. We find it more efficient to follow the Kugo-Uehara scheme which consists of (i) extending the superfield theory to a super-Weyl invariant system; and then (ii) applying a plain component reduction along with imposing a suitable super-Weyl gauge condition. This scheme is implemented in order to derive the bosonic action of the SL(2,R) duality invariant coupling to the dilaton-axion chiral multiplet and a Kähler sigma-model.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

McCarthy, Shane A. "Topics in nonlinear self-dual supersymmetric theories /." Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0045.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Whiting, Catherine Ann. "Duality symmetries in string-inspired supergravity: T-dualities and the gauge/gravity correspondence." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1796.

Повний текст джерела

Анотація:

Motivated by the AdS/CFT correspondence, new supersymmetric solutions to Type IIB and Type IIA supergravity are presented. These solutions contain $AdS_5$ or $AdS_4$ factors and are generated using T-duality symmetries of supergravity. The technique used to generate these solutions consists of performing a series of non-Abelian and Abelian T-dualities, sometimes with coordinate shifts in-between, to Freund-Rubin type seed backgrounds. An added bonus of the gauge fixing procedure inherent in non-Abelian T-Duality is the freedom to generate backgrounds with extra free parameters, some examples of which are presented. Aspects of the dual field theories of these new solutions are analyzed using holography techniques. The supersymmetry of these new backgrounds is also discussed. In addition to supergravity backgrounds with AdS, the study of generalized Calabi-Yau manifolds in the context of flux compactifications is briefly reviewed. The particular case of the resolved cone over $Y^{p,q}$ and its admission of generalized SU(3) structure solutions is examined. Contrary to geometries with $AdS$ factors, whose field theory duals are conformal field theories, these types of geometries can be phenomenologically interesting to study, as their gauge theory duals are minimally supersymmetric and confining, thus they could someday help aid our understanding of strongly-coupled QCD (Quantum Chromodynamics).

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Davies, N. Michael. "Semiclassical monopole calculations in supersymmetric gauge theories." Thesis, Durham University, 2000. http://etheses.dur.ac.uk/4360/.

Повний текст джерела

Анотація:

We investigate semiclassical contributions to correlation functions in N = 1 supersymmetric gauge theories. Our principal example is the gluino condensate, which signals the breaking of chiral symmetry, and should be exactly calculable, according to a persymmetric non-renormalisation theorem. However, the two calculational approaches previously employed, SCI and WCI methods, yield different values of the gluino condensate. We describe work undertaken to resolve this discrepancy, involving a new type of calculation in which the space is changed from R(^4) to the cylinder R(3) x S(1) This brings control over the coupling, and supersymmetry ensures that we are able to continue to large radii and extract answers relevant to R(^4). The dominant semiclassical configurations on the cylinder are all possible combinations of various types of fundamental monopoles. One specific combination is a periodic instanton, so monopoles are the analogue of the instanton partons that have been conjectured to be important at strong coupling. Other combinations provide significant contributions that are neglected in the SCI approach. Monopoles are shown to generate a superpotential that determines the quantum vacuum, where the theory is confining. The gluino condensate is calculated by summing the direct contributions from all fundamental monopoles. It is found to be in agreement with the WCI result for any classical gauge group, whereas the values for the exceptional groups have not been calculated before. The ADS superpotential, which describes the low energy dynamics of matter in a supersymmetric gauge theory, is derived using monopoles for all cases where instantons do not contribute. We report on progress made towards a two monopole calculation, in an attempt to quantify the missed contributions of the SCI method. Unfortunately, this eventually proved too complicated to be feasible.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Winding, Jacob. "Localization, supersymmetric gauge theories and toric geometry." Doctoral thesis, Uppsala universitet, Teoretisk fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-318668.

Повний текст джерела

Анотація:

Gauge theories is one of the most pervasive and important subject of modern theoretical physics, and there are still many things about them we do not understand. In particular dealing with strongly coupled theories where normal perturbative techniques do not apply is a fundamental open problem. In this thesis, we study a particular class of toy-models that have supersymmetry, which makes them much easier to deal with. We employ the mathematical technique of localization, which for supersymmetric theories lets us evaluate certain path integrals exactly and for any value of the coupling. This is used to study the 5d N=1 theories placed on toric Sasaki-Einstein manifolds and compute their partition functions, finding that they factorize into a product of contributions from each closed Reeb orbit of the manifold. This computation leads us to define two new hierarchies of special functions associated to these manifolds, and we study their properties. Finally, we use the 5d N=1 theories to construct new 4d N=2 theories on a large class of curved backgrounds. These theories have some interesting features, such as supporting both instantons and anti-instantons, and having a position-dependent complexified coupling constant.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Senoguz, Vedat Nefer. "Aspects of inflationary models and unification." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 114 p, 2007. http://proquest.umi.com/pqdweb?did=1251906411&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

22

LEGRAMANDI, ANDREA. "Supergravity solution classifications through bispinors." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2020. http://hdl.handle.net/10281/257788.

Повний текст джерела

Анотація:

Questa tesi si concentra sulla classificazione delle soluzioni di supergravità in dieci e undici dimensioni. Imponendo la supersimmetria, la supergravità rivela una pletora di eleganti strutture geometriche che possono essere definite dai parametri fermionici. Tali dati geometrici sono chiamati bispinori e sono l'argomento centrale di questa tesi. Nella prima parte esploriamo come sia possibile sfruttare i bispori per ottenere una riformulazione più elegante delle condizioni di supersimmetria. Questa discussione si svolge in un contesto generale senza assumere alcuna fattorizzazione dello spazio-tempo. Il formalismo bispinoriale consente inoltre di interpretare molte delle nuove equazioni di supersimmetria come condizioni di calibrazione per le sorgenti, dover per calibrazioni si intende una forma differenziale che identifica le brane con energia minima. Verranno discusse anche la connessione tra calibrazioni e la disuguaglianza BPS e verrà data una definizione delle cariche centrali in termini puramente gravitazionali. A parte questi risultati formali, probabilmente il principale successo del formalismo bispinoriale è che semplifica drasticamente il compito di classificare le soluzioni di supergravità. Dopo aver discusso come applicare queste tecniche nel caso AdS bidimensionale e Minkowski quadridimensionali, eseguiremo una classificazione completa sia della supergravità di tipo II sia della M-teoria delle soluzioni Minkowski quadridimensionali che preservano due supercariche con gruppo di R -simmetria SU(2) realizzato geometricamente da una sfera due-dimensionale nello spazio interno. Per i vari casi della classificazione, il problema di trovare soluzioni supersimmetriche può essere ridotto a un sistema di equazioni differenziali alle derivate parziali. Questi casi spesso ospitano sistemi di brane intersecanti e soluzioni anti-de-Sitter di dimensioni superiori. Inoltre mostriamo che, concatendando varie dualità, tutte le soluzioni possono essere generate da una fra due classi principali: una SU(2)-struttura in M-teoria e una Calabi-Yau conforme nel tipo IIB. Nell'ultima parte della tesi, mostriamo che è possibile rilassare alcune delle equazioni bispinoriali e generalizzare tutta la classificazione in un contesto più ampio con supersimmetria rotta.
This thesis focuses on classification of supergravity solutions in ten and eleven dimensions. By imposing supersymmetry, supergravity reveals a plethora of elegant geometric structures which can be defined from the fermionic supersymmetry parameters. Such geometrical data are called bispinors and are the central topic of this thesis. In the first part we explore how it is possible to exploit bispinors in order to get a more elegant reformulation of background supersymmetry conditions. This discussion is performed in a general context without assuming any factorization of space-time. The bispinor framework allows to interpret many of the new supersymmetry equations as calibration conditions for sources, where a calibration is a differential form which detects branes with minimal energy. We also discuss the connection between calibrations and BPS bound and we provide a definition of central charges in purely gravitational terms. Aside from these formal results, probably the main achievement of the bispinor formalism is that it drastically simplifies the task of classifying supergravity solutions. After discussing how to apply these techniques to two-dimensional AdS and four-dimensional Minkowski backgrounds, we perform a complete classification in both type II supergravity and M-theory of four-dimensional Minkowski solutions preserving N = 2 supersymmetry with SU(2) R-symmetry geometrically realized by a round sphere factor in the internal space. For the various cases of the classification, the problem of finding supersymmetric solutions can be reduced to a system of partial differential equations. These cases often accommodate systems of intersecting branes and higher-dimensional anti-de-Sitter solutions. Moreover we show that, using chains of dualities, all solutions can be generated from one of two master classes: an SU(2)-structure in M-theory and a conformal Calabi–Yau in type IIB. In the last part of the thesis, we show that it is possible to relax some of the bispinor equations and generalizing all the classification to a larger non-supersymmetric context.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Pasternak, Antoine. "Dimers, Orientifolds, and Dynamical Supersymmetry Breaking." Doctoral thesis, Universite Libre de Bruxelles, 2021. https://dipot.ulb.ac.be/dspace/bitstream/2013/327657/3/Table.pdf.

Повний текст джерела

Анотація:

This thesis is devoted to the study of orientifolds and dynamical supersymmetry breaking in configurations of D-branes on toric Calabi-Yau singularities, through the lens of dimer models. We first review the basic ingredients of string theory that led to the formulation of gauge/gravity dualities in terms of dimers. Then, we discuss the non-abelian anomaly cancellation conditions for the supersymmetric gauge theories arising on D-branes and provide necessary geometric criteria to determine whether an orientifold projection can be safely introduced. We also find a new realization of orientifold projection without fixed loci in dimer models and expand on its physical features. We argue that it exhausts the possibilities of orientifolding dimer models. In the subsequent part of the thesis, we investigate dynamical supersymmetry breaking vacua in the same class of models and their typical instability along N=2 Coulomb branches. This leads us to formulate a no-go theorem against their stability based on geometrical features of the singularity, and then to establish a precise way to circumvent it. We eventually find the first instance of stable dynamical supersymmetry breaking vacuum in string theory from D-branes on a toric Calabi-Yau singularity, the Octagon.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Markou, Chrysoula. "Nonlinear supersymmetry, spontaneous supersymmetry breaking and extra dimensions." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS227.

Повний текст джерела

Анотація:

Le sujet de cette thèse est la brisure partielle de la supersymétrie N=2 en quatres et cinq dimensions de l'espace-temps. Dans le premiere cas, nous étudions hors de la couche de masse la réalisation non-linéaire de la supersymétrie N=1 brisée en utilisant de superchamps N=2 nilpotents qui contiennent les degrés de liberté de Goldstone du multiplet massif de N=1 de spin-3/2. Ces superchamps du Goldstino peuvent être de Maxwell ou de simple-tenseur. La brisure partielle est généré par une combinaison des termes électriques et magnétiques de Fayet-Iliopoulos, dont les coefficients peuvent être considérés comme de paramètres des déformations des transformations de l'algèbre de la supersymétrie brisée, ou, en plus, comme de déformations des superchamps eux-mêmes. D'interactions entre les multiplets du Goldstino deformés avec des multiplets pas deformés donne lieu à un mécanisme de super-Brout-Englert-Higgs mais sans la gravité, en raison duquel un multiplet N=1 vectoriel absorbe un multiplet N=1 linéaire et devient massif. Dans le deuxième cas, nous étudions sur la couche de masse la brisure partielle qui est généré par la valeur moyenne du dilaton qui est linéaire de la dimension supplémentaire et ce dernier est un modèle du dual holographique de little string theory. Un jaugement particulier de la supergravité N=2, D=5 peut incorporer cet modèle, et la supersymétrie N=1 reste intacte en quatres dimensions. Après compactification de la dimension supplémentaire, nous trouvons que l'introduction de branes est compatible avec la direction de la supersymétrie pas brisée
The subject matter of the present thesis is the partial breaking of N=2 supersymmetry in four and in five spacetime dimensions. In the first case, we study the off-shell nonlinear realization of the broken N=1 superymmetry with the use of nilpotent N=2 superfields that contain the Goldstone degrees of freedom of the massive spin-3/2 multiplet of N=1 supersymmetry. These Goldstino superfields can either be the Maxwell or the single-tensor multiplet. The partial breaking is induced by a combination of magnetic and electric Fayet-Iliopoulos terms, the coefficients of which can be seen as deformation parameters of the transformations of the broken supersymmetry algebra or, futhermore, as deformations of the superfields themselves. Interactions of deformed Goldstino multiplets with undeformed multiplets generate a super-Brout-Englert-Higgs effect but without gravity, in which an N=1 vector multiplet absorbs an N=1 linear multiplet and becomes massive. In the second case, we study on-shell the partial breaking that is induced by the background value of the dilaton that is linear in the extra dimension, with the latter being a toy model of the holographic dual of little string theory. A particular gauging of N=2, D=5 supergravity can accommodate this model, with N=1 supersymmetry remaining intact in four dimensions. Upon compactification of the extra dimension, we find that the introduction of branes is compatible with the direction of the unbroken supersymmetry

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Nedelin, Anton. "Exact Results in Five-Dimensional Gauge Theories : On Supersymmetry, Localization and Matrix Models." Doctoral thesis, Uppsala universitet, Teoretisk fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-243320.

Повний текст джерела

Анотація:

Gauge theories are one of the corner stones of modern theoretical physics. They describe the nature of all fundamental interactions and have been applied in multiple branches of physics. The most challenging problem of gauge theories, which has not been solved yet, is their strong coupling dynamics. A class of gauge theories that admits simplifications allowing to deal with the strong coupling regime are supersymmetric ones. For example, recently proposed method of supersymmetric localization allows to reduce expectation values of supersymmetric observables, expressed through the path integral, to finite-dimensional matrix integral. The last one is usually easier to deal with compared to the original infinite-dimensional integral. This thesis deals with the matrix models obtained from the localization of different 5D gauge theories. The focus of our study is N=1 super Yang-Mills theory with different matter content as well as N=1 Chern-Simons-Matter theory with adjoint hypermultiplets. Both theories are considered on the five-spheres. We make use of the saddle-point approximation of the matrix integrals, obtained from localization, to evaluate expectation values of different observables in these theories. This approximation corresponds to the large-N limit of the localized gauge theory. We derive $N^{3}$ behavior for the free energy of 5D N=1* super Yang-Mills theory at strong coupling. This result is important in light of the relation between 5D theory and the world-volume theories of M5-branes, playing a significant role in string theory. We have also explored rich phase structure of 5D SU(N) N=1 super Yang-Mills theory coupled to massive matter in different representations of the gauge group. We have shown that in the case of the massive adjoint hypermultiplet theory undergoes infinite chain of the third order phase transitions while interpolating between weak and strong coupling in the decompactification limit. Finally, we obtain several interesting results for 5D Chern-Simons theory, suggesting existence of the holographic duals to this theory. In particular, we derive $N^{5/2}$ behavior of the free energy of this theory, which reproduces the behavior of the free energy for 5D theories with known holographic duals.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Yokoo, Seiichiro. "Model for a fundamental theory with supersymmetry." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1182.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Barranco, López Alejandro. "Applications of Supersymmetry: Exact Results, Gauge/Gravity Duality and Condensed Matter." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/284195.

Повний текст джерела

Анотація:

The study of supersymmetry has led us to a better understanding of field theories, specially in the strong coupling regime. In this thesis we have tried to show this through several examples. These are: - The first of these examples has been the application of localization techniques in supersymmetric theories. Specifically, we have used the partition function of N=2 supersymmetric Chern-Simons theory with gauge group U(N) and 2Nf flavors. To regularize the theory, it is necessary to make the computation in a three sphere whose radius, R, serves as an IR regulator which can be taken to infinity at the end of the computation. Once we have the exact partition function in terms of a matrix integral, we can solve the integral by means of a saddle-point approximation. This approximation becomes exact in the large N limit. The saddle-point equation can be solved exactly and in the decompactification limit it shows different phases depending on the value of the 't Hooft coupling. We have also computed the free energy and the vacuum expectation value of a Wilson loop for a big circle of the three sphere. Both of them show discontinuities in their derivatives, in particular, the discontinuity in the free energy appears in the third derivative and thus, both phase transitions are third order. - Other application that we have seen consists of the use of the gauge/gravity duality. In particular, starting from the gravity dual to N=1 super Yang-Mills, proposed by Maldacena and Núñez, we have reviewed how to add flavors (quarks) to this theory, without mass first and with mass later. We have also seen how to extract information about the field theory from these gravity duals, we have paid special attention to how the beta-function of the field theory dual is obtained from the gravity background proposed by Conde, Gaillard and Ramallo, dual to N=1 super Yang-Mills field theory with Nf massive flavors and a quartic superpotential. The main result from the point of view of the field theory is that, in the case Nf=2N, the beta-function shows a non-trivial UV fixed point, which hints on possible IR fixed point as proposed by Seiberg in the conformal window picture. No evidence of non-trivial fixed points is found for Nf different from 2N. - Again, in the context of the gauge/gravity duality, we have studied how to generate new supergravity solutions applying T-duality and how this affects the G-structures that describe the supersymmetry of these solutions. We have applied T-duality to the IIB supergravity solution of Klebanov and Witten with flavors. The supersymmetry of these backgrounds can be described by an SU(3)-structure and an SU(2)-structure before and after T-dualizing, respectively. - Finally, we have presented an N=1 supersymmetric model that exhibits a superconducting phase transition. This model is based on a quartic Kähler potential for a chiral multiplet and no superpotential. The main difference with standard superconductivity is that the phase transition becomes first order rather than second order. Another difference is that, as it is typical in supersymmetric theories, the dependence on the cut-off is softened in our model.
El estudio de supersimetría nos ha permitido un mejor entendimiento de las teorías de campos, especialmente en el régimen de acoplamiento fuerte. En esta tesis hemos tratado de mostrar esto a través de varios ejemplos. A saber: - Primero hemos mostrado cómo calcular de manera exacta con técnicas de localización la función de partición de la teoría de Chern-Simons supersimétrica N=2 con grupo gauge U(N) y 2Nf sabores en una tres esfera. Una vez que tenemos la función de partición exacta en términos de una integral de matrices, podemos resolverla por medio de la aproximación de punto silla. Esta aproximación se vuelve exacta cuando tomamos el límite de N grande. En el límite de descompactificación calculamos la energía libre y el valor de expectación de un lazo de Wilson correspondiente a un círculo máximo de la tres-esfera, mostrando transiciones de fase de tercer orden. - Otra aplicación ha consistido en el uso de la dualidad gravedad/gauge. Hemos revisado como construir una solución de supergravedad dual a la teoría N=1 super Yang-Mills con Nf sabores masivos y un superpotencial cuártico. El principal resultado desde el punto de vista de la teoría de campos que corresponde a dicha solución, consiste en que, en el caso Nf=2N, la función beta exhibe un punto fijo UV no trivial que da lugar a indicios acerca de un punto fijo IR adicional tal y como propone Seiberg en su propuesta de la ventana conforme. - También en el contexto de la dualidad gravedad/gauge hemos estudiado cómo generar nuevas soluciones de supergravedad por medio de la aplicación de T-dualidad a la solución de supergravedad de Klebanov y Witten con sabores. La supersimetría de estas soluciones pueden ser descritas en términos de una SU(3) estructura antes de T-dualizar, o una SU(2)-estructura, después de T-dualizar. - Finalmente, hemos presentado un modelo supersimétrico que exhibe una transición de fase superconductora basado en un potencial de Kähler cuártico para un multiplete quiral y sin superpotencial. Encontramos dos diferencias con superconductores usuales: nuestro modelo exhibe una transición de fase de primer orden, en lugar de ser de segundo orden, y la dependencia con la energía de corte es más suave.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

LEONI, MARTA. "SCATTERING AMPLITUDES IN SUPERCONFORMAL GAUGE THEORIES." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/259356.

Повний текст джерела

Анотація:

Superconformal field theories have been widely explored over the last years, especially because of their large amount of symmetry which allows to derive exact results. The most prominent example within this class is the four-dimensional maximally supersymmetric N = 4 Super Yang-Mills theory, which played a pivotal role in the proposal of the AdS/CFT correspondence, a conjectured weak/strong duality relating superconformal gauge theories to string theories on curved backgrounds. Soon after the formulation of the correspondence the presence of integrable structures was discovered both in planar N = 4 SYM and in its string counterpart, and since then integrability in superconformal theories became one of the main research topics in theoretical physics. Interestingly, integrability in N = 4 was later shown to be intimately related to the presence of the so called dual conformal symmetry, a hidden symmetry of the planar amplitudes that puts even stronger constraints on their structure. This suggests that some crucial aspects of a theory can be investigated through the computation of its scattering amplitudes, which can thereby provide a powerful tool also for the study of less supersymmetric superconformal field theories. In particular it is essential to understand whether some of the beautiful properties of N = 4 survives when supersymmetry is not maximal. In this thesis we present computations of massless scattering amplitudes in two different not maximally supersymmetric conformal theories: N = 2 superconformal QCD in four dimensions and N = 6 Chern-Simons matter theory (ABJM) in three dimensions. In N = 2 SCQCD we compute all possible four-point amplitudes at one loop and the two-loop amplitude with fundamental fields as external legs. In ABJM we extend the two-loop computation of four-point scattering amplitudes and of the Sudakov form factor beyond the planar limit. We also discuss our results in relation to the corresponding ones in N = 4 SYM, paying particular attention to the possible presence of dual conformal invariance and to maximum transcendentality.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Araujo, Thiago Rocha [UNESP]. "Some aspects of abelian and nonabelian T-duality and the gauge/gravity correspondence." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/134300.

Повний текст джерела

Анотація:

Submitted by THIAGO ROCHA ARAUJO (taraujo@ift.unesp.br) on 2016-02-18T13:06:31Z No. of bitstreams: 1 thesis.pdf: 2041737 bytes, checksum: e20834514f664eb4d2cf9905a1e49015 (MD5)
Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-02-19T19:04:25Z (GMT) No. of bitstreams: 1 araujo_tr_dr_ift.pdf: 2041737 bytes, checksum: e20834514f664eb4d2cf9905a1e49015 (MD5)
Made available in DSpace on 2016-02-19T19:04:25Z (GMT). No. of bitstreams: 1 araujo_tr_dr_ift.pdf: 2041737 bytes, checksum: e20834514f664eb4d2cf9905a1e49015 (MD5) Previous issue date: 2016-02-16
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Nessa tese estudamos propriedades de soluções de supergravidade tipo II obtidas através da dualidade T abeliana e não abeliana. Também determinamos, através da conjectura gauge/gravidade, aspectos da teoria de campos dual a essas soluções obtidas por dualidade T. Consideramos três tipos distintos de soluções: duais a teorias de campos que confinam, duais a teoria de campos conformes e duais a teoria de campos não-relativistas. Concluimos essa tese com uma análise dos laços de Wilson em soluções com simetria não relativista.
In this thesis we study properties of type II supergravity solutions generated by abelian and nonabelian T-duality. Also we determine, through the gauge/gravity conjecture, some aspects of the field theory dual to the supergravity solutions obtained by T-dualization. We consider three distinct types of backgrounds solutions, namely, backgrounds that are dual to confining field theories, backgrounds dual to conformal field theories and those dual to nonrelativistic field theories. We conclude this thesis with an analysis of Wilson loops on backgrounds with nonrelativistic symmetries.
CNPq: 140588/2012-4

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Endres, Michael G. "Topics in lattice field theory /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/9713.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

31

ROSA, DARIO. "From spinors to forms: results on g-structures in supergravity and on topological field theories." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2014. http://hdl.handle.net/10281/55207.

Повний текст джерела

Анотація:

This thesis is divided in two parts, that can be read separately even if both use the possibility of replacing spinors with differential forms in theories with supersymmetry. The ﬁrst part explores some recent results that have been obtained by applying the G-structure approach to type II supergravities. Using generalized complex geometry it is possible to reformulate the conditions for unbroken supersymmetry in type II supergravity in terms of differential forms. We use this result to ﬁnd a classiﬁcation for AdS7 and AdS6 solutions in type II supergravity. Concerning AdS7 solutions we ﬁnd that in type IIB no solutions can be found, whereas in massive type IIA many new AdS7×M3 solutions are at disposal with the topology of the internal manifold M3 given by a three-sphere. We develop a classiﬁcation for such solutions. Concerning AdS6 solutions, very few AdS6×M4 supersymmetric solutions are known in literature: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique. We obtain a classiﬁcation for IIB supergravity, by reducing the problem to two PDEs on a two-dimensional space Σ. The four-dimensional space M4 is then given by a ﬁbration of S2 over Σ. We also explore other two contexts in which the G-structure approach has revealed its usefulness: ﬁrst of all we derive the conditions for unbroken supersymmetry for a Mink2 (2,0) vacuum, arising from type II supergravity on a compact eight-dimensional manifold M8. When M8 enjoys SU(4)×SU(4) structure the resulting system is elegantly rewritten in terms of generalized complex geometry. Finally we rewrite the equations for ten-dimensional supersymmetry in a way formally identical to an analogous system in N = 2 gauged supergravity; this provides a way to look for lifts of BPS solutions without having to reduce the ten-dimensional action. The second part is devoted to study some aspects of two different Chern-Simons like theories: holomorphic Chern-Simons theory on a six-dimensional Calabi-Yau space and three-dimensional supersymmetric theories involving vector multiplets (both with Yang-Mills and Chern-Simons terms in the action). Concerning holomorphic Chern-Simons theory, we construct an action that couples the gauge ﬁeld to off-shell gravitational backgrounds, comprising the complex structure and the (3,0)-form of the target space. Gauge invariance of this off-shell action is achieved by enlarging the ﬁeld space to include an appropriate system of Lagrange multipliers, ghost and ghost-for-ghost ﬁelds. From this reformulation it is possible to uncover a twisted supersymmetric algebra for this model that strongly constrains the anti-holomorphic dependence of physical correlators. Concerning three-dimensional theories, we will develop a new way of computing the exact partition function of supersymmetric three-dimensional gauge theories, involving vector supermultiplet only. Our approach will reduce the problem of computing the exact partition function to the problem of solving an anomalous Ward identity. To obtain such a result we will describe the coupling of three-dimensional topological gauge theories to background topological gravity. The Seifert condition for manifolds supporting global supersymmetry is elegantly deduced from the topological gravity BRST transformations. We will show how the geometrical moduli that affect the partition function can be characterized cohomologically. In the Seifert context Chern-Simons topological (framing) anomaly is BRST trivial and we will compute explicitly the corresponding local Wess-Zumino functional. As an application, we obtain the dependence on the Seifert moduli of the partition function of three-dimensional supersymmetric gauge theory on the squashed sphere by solving the anomalous topological Ward identities, in a regularization independent way and without the need of evaluating any functional determinant.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Bevilaqua, Leandro Ibiapina. "\"Branas em supergravidade\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29032007-211600/.

Повний текст джерела

Анотація:

Este trabalho tem o objetivo de rever a obtenção das soluções do tipo brana em supergravidade e contém uma dedução detalhada das soluções extrema e negra. A fim de motivar algumas escolhas feitas ao longo do cálculo, o trabalho inclui uma breve revisão dos conceitos advindos da teoria de cordas e supersimetria. Esta revisão nos permitirá ainda relacionar as soluções da supergravidade com as branas da teoria de cordas e tecer considerações sobre o papel desta relação na dualidade entre teoria de calibre e gravitação.
This work intends to review the brane solutions of supergravity and contains a datailed deduction of the extremal and black solutions. In order to provide some motivations to the choices through the calculation, this work includes a brief review of some concepts from string theory and supersymmetry. This review will enable us to relate the supergravity solutions to string theory\'s branes and to make considerations about the role of this relationship in the duality between gauge and gravity theories.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Ortiz, Thomas. "Two dimensional Maximal Supergravity, Consistent Truncations and Holography." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2014. http://tel.archives-ouvertes.fr/tel-01070735.

Повний текст джерела

Анотація:

A complete non trivial supersymmetric deformation of the maximal supergravity in two dimensions is achieved by the gauging of a SO(9) group. The resulting theory describes the reduction of type IIA supergravity on an AdS_2 x S^8 background and is of first importance in the Domain-Wall / Quantum Field theory correspondence for the D0-brane case. To prepare the construction of the SO(9) gauged maximal supergravity, we focus on the eleven dimensional supergravity and the maximal supergravity in three dimensions since they give rise to important off-shell inequivalent formulations of the ungauged theory in two dimensions. The embedding tensor formalism is presented, allowing for a general desciption of the gaugings consistent with supersymmetry. The SO(9) supergravity is explicitly constructed and applications are considered. In particular, an embedding of the bosonic sector of the two-dimensional theory into type IIA supergravity is obtained. Hence, the Cartan truncation of the SO(9) supergravity is proved to be consistent. This motivated holographic applications. Therefore, correlation functions for operators in dual Matrix models are derived from the study of gravity side excitations around half BPS backgrounds. These results are fully discussed and outlooks are presented.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Closset, Cyril. "Studies of fractional D-branes in the gauge/gravity correspondence & flavored Chern-Simons quivers for M2-branes." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210125.

Повний текст джерела

Анотація:

Cette thèse intitulée « Studies of fractional D-branes in the gauge/gravity correspondence & Flavored Chern-Simons quivers for M2-branes » se place dans le cadre de la théorie des cordes, en physique théorique. Elle consiste en une introduction suivie de deux parties. Dans l'introduction sont résumés les différents outils de théorie des cordes qui seront utilisés.

\
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Nolland, David John. "Quantum field theories with fermions in the Schrödinger representation." Thesis, Durham University, 2000. http://etheses.dur.ac.uk/4410/.

Повний текст джерела

Анотація:

This thesis is concerned with the Schrödinger representation of quantum field theory. We describe techniques for solving the Schrödinger equation which supplement the standard techniques of field theory. Our aim is to develop these to the point where they can readily be used to address problems of current interest. To this end, we study realistic models such as gauge theories coupled to dynamical fermions. For maximal generality we consider particles of all physical spins, in various dimensions, and eventually, curved spacetimes. We begin by considering Gaussian fields, and proceed to a detailed study of the Schwinger model, which is, amongst other things, a useful model for (3+1) dimensional gauge theory. One of the most important developments of recent years is a conjecture by Mal-dacena which relates supergravity and string/M-theory on anti-de-Sitter spacetimes to conformal field theories on their boundaries. This correspondence has a natural interpretation in the Schrödinger representation, so we solve the Schrödinger equation for fields of arbitrary spin in anti-de-Sitter spacetimes, and use this to investigate the conjectured correspondence. Our main result is to calculate the Weyl anomalies arising from supergravity fields, which, summed over the supermultiplets of type JIB supergravity compactified on AdS(_s) x S(^5) correctly matches the anomaly calculated in the conjecturally dual N = 4 SU{N) super-Yang-Mills theory. This is one of the few existing pieces of evidence for Maldacena's conjecture beyond leading order in TV.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

O'Bannon, Andrew Hill. "Holographic thermodynamics and transport of flavor fields /." Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/9785.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Koehl, Christian. "Geometry of supersymmetric sigma models and D-brane solitons." Thesis, Queen Mary, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325106.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Wulff, Linus. "Strings, boundary fermions and coincident D-branes." Doctoral thesis, Stockholm : Department of Physics, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6576.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Lotito, Matteo. "Geometric classification of 4d rank-1 N=2 superconformal field theories." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1530880263562131.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Grozdanov, Saso. "Hydrodynamics : from effective field theory to holography." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:c00bd3e6-3b52-41d5-8542-2f2d55fc8741.

Повний текст джерела

Анотація:

Hydrodynamics is an effective theory that is extremely successful in describing a wide range of physical phenomena in liquids, gases and plasmas. However, our understanding of the structure of the theory, its microscopic origins and its behaviour at strong coupling is far from complete. To understand how an effective theory of dissipative hydrodynamics could emerge from a closed microscopic system, we analyse the structure of effective Schwinger-Keldysh Closed-Time-Path theories. We use this structure and the action principle for open systems to derive the energy-momentum balance equation for a dissipative fluid from an effective CTP Goldstone action. Near hydrodynamical equilibrium, we construct the first-order dissipative stress-energy tensor and derive the Navier-Stokes equations. Shear viscosity is shown to vanish, while bulk viscosity and thermodynamical quantities are determined by the form of the effective action. The exploration of strongly interacting states of matter, particularly in the hydrodynamic regime, has been a major recent application of gauge/string duality. The strongly coupled theories involved are typically deformations of large-$N$ SUSY gauge theories with exotic matter that are unusual from a low-energy point of view. In order to better interpret holographic results, an understanding of the weak-coupling behaviour of such gauge theories is essential. We study the exact and SUSY-broken N=1 and N=2 super-QED with finite densities of electron number and R-charge, respectively. Despite the fact that fermionic fields couple to the chemical potentials, the strength of scalar-fermion interactions, fixed by SUSY, prevents a Fermi surface from forming. This is important for hydrodynamical excitations such as zero sound. Intriguingly, in the absence of a Fermi surface, the total charge need not be stored in the scalar condensates alone and fermions may contribute. Gauss-Bonnet gravity is a useful laboratory for non-perturbative studies of the higher derivative curvature effects on transport coefficients of conformal fluids with holographic duals. It was previously known that shear viscosity can be tuned to zero by adjusting the Gauss-Bonnet coupling, λ_GB, to its maximal critical value. To understand the behaviour of the fluid in this limit, we compute the second-order transport coefficients non-perturbatively in λ_GB and show that the fluid still produces entropy, while diffusion and sound attenuation are suppressed at all order in the hydrodynamic expansion. We also show that the theory violates a previously proposed universal relation between three of the second order transport coefficients. We further compute the only second-order coefficient thus far unknown, λ₂, in the N=4 super Yang-Mills theory with the leading-order 't Hooft coupling correction. Intriguingly, the universal relation is not violated by these leading-order perturbative corrections. Finally, by adding higher-derivative photon field terms to the action, we study charge diffusion and non-perturbative parameter regimes in which the charge diffusion constant vanishes.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Lucena, Gomez Gustavo. "Aspects of higher-spin theory with fermions." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209320.

Повний текст джерела

Анотація:

The present thesis is divided into three parts. In Part I we address a problem within Higher-Spin Gauge Theory in dimension three: namely, that of computing the asymptotic symmetry algebra of supersymmetric models, describing an infinite spectrum of integer and half-integer higher-spin fields. In Part II we investigate higher-spin theories in dimension four or greater, where we classify the consistent cross interactions between free gauge fermions of arbitrary spin and a photon or a graviton. A third part supplements the bulk of the manuscript with technical appendices.

Part I is concerned with the Higher-Spin Theory extending the anti-de Sitter orthosymplectic Supergravity in three dimensions. After recalling the construction of the latter we exhibit the structure of the former, and then explain how to generalize the boundary conditions for Supergravity to the higher-spin case. Following the usual procedure, we compute the form of the residual gauge parameter and then identify the Poisson-bracket algebra governing the asymptotic dynamics. It is found to be a nonlinear, supersymmetric algebra of the W-infinity type with same central charge as pure Gravity in the Virasoro sector, which is a subalgebra thereof. The simply supersymmetric case is treated explicitly whereas the details of the extended cases are relegated to the appendices.

Part II deals with the interaction problem for gauge fermions coupled to Electromagnetism and Gravity in flat spacetime of arbitrary dimension. First we recall the so-called BRST-Antifield techniques, which reformulate the deformation problem as a cohomological one, recasting the familiar Noether procedure for finding out interactions in a mathematically systematic way. We then use these methods to classify and obtain expressions for the gauge-invariant cubic couplings between a symmetric tensor-spinor and a spin-1 and spin-2 gauge field. With no input from previous works, we find the complete list of interaction terms with minimal assumptions and in particular shed light on the quartic obstructions to full consistency.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Moskovic, Micha. "Holographic backgrounds from D-brane probes." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209307.

Повний текст джерела

Анотація:

The gauge/string correspondence provides a non-perturbative definition of string theory and hence quantum gravity in some backgrounds, making it possible to translate statements about strongly coupled quantum field theories into results about gravity.

In this thesis, we focus on the derivation of holographic backgrounds from the field theory, without using any supergravity input. Instead, we rely crucially on the addition of probe D-branes to the stack of D-branes generating the background.

From the field theory description of the probe branes in the presence of the background branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the D-brane probe action in a generic supergravity background then allows to determine the holographic background dual to the considered field theory vacuum.

In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons.

The second part contains the original results of this thesis, obtained by applying this strategy to several specific examples. We first derive the duals to three continuous deformations (Coulomb branch, β and non-commutative deformations) of the basic case, in the limit in which the D-instantons can probe the full geometry. We then derive the enhançon mechanism in a dual to a simple N=2 quiver gauge theory by using a fractional D-instanton as a probe and exploiting recent exact results on the Coulomb branch of N=2 quivers.

Finally, we obtain the near-horizon D4-brane geometry by probing the D4-branes with a small number of D0-branes.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Filho, Sergio Augusto Jardino. "Cordas em espaços deformados." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11052009-155920/.

Повний текст джерела

Анотація:

Nesta tese foram estudadas configurações de cordas em movimentos de rotação e de oscilação no âmbito da correspondência AdS/CFT. Estas cordas movimentam-se nos espaços AdS5 × S5, de Lunin e Maldacena, R1, 9 e R1, 9 deformado. Para o caso da corda em rotação, determinou-se a existência do mágnon gigante e da corda farpada. Para o caso da corda oscilante, foram encontradas as soluções das equações de movimento clássicas e determinada a energia. Também calculamos explicitamente o número de supercargas preservadas para os espaços AdS5 × S5 e para R1, 9 deformado.
In this thesis we studied rotating and oscillating strings under the AdS/CFT correspondence. These strings move in the AdS5 × S5, Lunin and Maldacena, R1, 9 and deformed R1, 9 spaces. In the case of the rotating string, the giant magnon and the spiky string were determined. In the case of the oscillating string, we found the solutions fo the classical equations of motion and the energy. We also explicitly calculated the number of preserved supercharges for the AdS5 × S5and deformed R1, 9 spaces.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Schuster, Theodor. "Scattering amplitudes in four- and six-dimensional gauge theories." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/17034.

Повний текст джерела

Анотація:

Streuamplituden der Quantenchromodynamik (QCD), N = 4 Super-Yang-Mills-Theorie (SYM-Theorie) und der sechsdimensionalen N = (1, 1) SYM-Theorie werden untersucht, mit einem Fokus auf die Symmetrien und Relationen zwischen den Streuamplituden dieser Eichtheorien auf dem Baum-Niveau. Die Baum-Niveau- und Ein-Schleifen-Farbzerlegung beliebiger QCD-Amplituden in primitive Amplituden wird bestimmt und Identitäten hergeleitet, welche den Nullraum unter den primitiven Amplituden aufspannen. Anschließend wird bewiesen, dass alle farbgeordneten Baum-Niveau-Amplituden der masselosen QCD aus der N = 4 SYM-Theorie erhalten werden können. Analytische Formeln für alle für die QCD relevanten N = 4 SYM-Amplituden werden bestimmt und die Effizienz und Genauigkeit der numerischen Auswertung der analytischen Formeln für farbgeordnete QCD-Baum-Niveau-Amplituden mit einer effizienten numerischen Implementierung der Berends-Giele-Rekursion verglichen. Die Symmetrien der massive Amplituden auf dem Coulomb-Zweig der N = 4 SYM-Theorie werden hergeleitet. Diese können durch eine dimensionale Reduktion der masselosen Baum-Niveau-Amplituden der sechsdimensionalen N = (1, 1) SYM-Theory erhalten werden. Darüber hinaus wird bezeigt, wie es mit Hilfe einer numerischen Implementierung der BCFW-Rekursion möglich ist analytische Formeln für die Baum-Niveau-Superamplituden der N = (1, 1) SYM-Theory zu erhalten und die Möglichkeit eines Uplifts der masselose Baum-Niveau-Amplituden der N = 4 SYM-Theory untersucht. Schließlich wird eine Alternative zur dimensionalen Regularisierung der N = 4 SYM-Theorie untersucht. Die Infrarotdivergenzen werden hierbei durch Massen regularisiert, die durch einen Higgs-Mechanismus erhalten wurden. Die korrespondierende Stringtheorie-Beschreibung deutet auf eine exakte duale konforme Symmetrie der Streuamplituden hin. Durch explizite Rechnungen wird dies bestätigt und Vorteile des Regulators werden demonstriert.
We study scattering amplitudes in quantum chromodynamics (QCD), N = 4 super Yang-Mills (SYM) theory and the six-dimensional N = (1, 1) SYM theory, focusing on the symmetries of and relations between the tree-level scattering amplitudes in these three gauge theories. We derive the tree level and one-loop color decomposition of an arbitrary QCD amplitude into primitive amplitudes. Furthermore, we derive identities spanning the null space among the primitive amplitudes. We prove that every color ordered tree amplitude of massless QCD can be obtained from gluon-gluino amplitudes of N = 4 SYM theory. Furthermore, we derive analytical formulae for all gluon-gluino amplitudes relevant for QCD. We compare the numerical efficiency and accuracy of evaluating these closed analytic formulae for color ordered QCD tree amplitudes to a numerically efficient implementation of the Berends-Giele recursion. We derive the symmetries of massive tree amplitudes on the coulomb branch of N = 4 SYM theory, which in turn can be obtained from N = (1, 1) SYM theory by dimensional reduction. Furthermore, we investigate the tree amplitudes of N = (1, 1) SYM theory and explain how analytical formulae can be obtained from a numerical implementation of the supersymmetric BCFW recursion relation and investigate a potential uplift of the massless tree amplitudes of N = 4 SYM theory. Finally we study an alternative to dimensional regularization of N = 4 SYM theory. The infrared divergences are regulated by masses obtained from a Higgs mechanism. The corresponding string theory set-up suggests that the amplitudes have an exact dual conformal symmetry. We confirm this expectation and illustrate the calculational advantages of the massive regulator by explicit calculations.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Ntokos, Praxitelis. "Flux backgrounds, AdS/CFT and Generalized Geometry." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066206/document.

Повний текст джерела

Анотація:

La recherche de solutions du vide en présence de flux non-triviaux dans la théorie des cordes est importante pour la construction de modèles pertinents à la phénomenologie de la physique des particules. Dans le cadre de la correspondance AdS/CFT, les théories de jauge en 4d, considérées comme descendantes de N=4 SYM, sont duales à des configurations de champs en 10d avec des géometries ayant un facteur AdS_5 asymptotiquement. Dans cette thèse, nous étudions des déformations de masse qui brisent la supersymétrie (partiellement ou totalement) du côté de la théorie des champs et qui sont duales aux états de la théorie IIB avec flux non-nuls du côté gravitique. Les équations du mouvement de la supergravité contraignent les paramètres de la théorie de jauge à satisfaire certaines relations. En particulier, nous trouvons que la somme des carrés de la masse des bosons est égale à celle fermions, rendant ces modèles problematiques pour des applications phénomenologiques. L'étude des théories duales de supergravité pour des déformations plus générales de la théorie conforme des champs exige des techniques qui vont au-delà des outils géometriques standards. La Géometrie Généralisée Exceptionelle fournit une façon très élégante d'intégrer les flux de supergravité dans la géometrie. Nous examinons les solutions AdS_5 avec des flux génériques conservants huit supercharges et nous montrons que celles-ci satisfont des relations particulièrement simples qui ont une interprétation géometrique dans le cadre de la Géometrie Généralisée. Ceci ouvre la voie pour l'étude systématique des déformations marginales supersymétriques de la théorie
The search for string theory vacuum solutions with non-trivial fluxes is of particular importance for the construction of models relevant for particle physics phenomenology. In the framework of the AdS/CFT correspondence, four-dimensional gauge theories which can be considered to descend from N = 4 SYM are dual to ten- dimensional field configurations with geometries having an asymptotically AdS_5 factor. In this Thesis, we study mass deformations that break supersymmetry (partially or entirely) on the field theory side and which are dual to type IIB backgrounds with non-zero fluxes on the gravity side. The supergravity equations of motion constrain the parameters on the gauge theory side to satisfy certain relations. In particular, we find that the sum of the squares of the boson masses should be equal to the sum of the squares of the fermion masses, making these set-ups problematic for phenomenology applications. The study of the supergravity duals for more general deformations of the conformal field theory requires techniques which go beyond the standard geometric tools. Exceptional Generalized Geometry provides a very elegant way to incorporate the supergravity fluxes in the geometry. We study AdS_5 backgrounds with generic fluxes preserving eight supercharges and we show that these satisfy particularly simple relations which admit a geometrical interpretation in the framework of Generalized Geometry. This opens the way for the systematic study of supersymmetric marginal deformations of the conformal field theory in the context of AdS/CFT

Стилі APA, Harvard, Vancouver, ISO та ін.

46

CASSIA, LUCA. "Aspects of Compactifications and Dualities in Superconformal Theories." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2019. http://hdl.handle.net/10281/241119.

Повний текст джерела

Анотація:

Questa tesi tratta di vari aspetti non perturbativi delle teorie di gauge supersimmetriche nelle dimensioni 2,3 e 4 e delle diverse costruzioni che mettono in relazione proprietà di teorie di campo superconformi tra diverse dimensionalità. Sono state applicate varie tecniche tra cui la più importante è la riduzione dimensionale e la compattificazione con decorazioni delle varietà interne. La tesi tratta di due argomenti principali; il primo è lo studio delle compattificazioni delle teorie del campo superconformi in 4d poste su una superficie di Riemann con una particolare scelta di "background" lungo le dimensioni interne, la cui scelta è imposta dal requisito che la supersimmetria non sia rotta dalla geometria curva. Un'analisi approfondita di questa costruzione viene effettuata a livello formale per ogni genus sia per supersimmetria minima che estesa. I risultati ottenuti forniscono una classificazione sistematica di tutte le teorie 2d che possono essere costruite attraverso questa tecnica. I risultati sono quindi applicati allo studio di specifici modelli 4d. Limitandoci ad una specifica classe di teorie dotate di una struttura torica sul loro spazio dei moduli, siamo in grado di mostrare una connessione diretta tra la geometria torica e la forma esplicita della carica centrale e delle anomalie in 2d. Il secondo argomento è lo studio delle compattificazioni su cerchio delle dualità 4d. Consideriamo la riduzione della dualità di Seiberg e le sue generalizzazioni a SQCD con gruppi di gauge simplettici, campi nell'aggiunta e nella fondamentale. Un'interessante proprietà di queste teorie 4d, chiamata "E7 surprise", si estende a 3d e si dimostra responsabile della comparsa nell'infrarosso di un pattern di dualità e di "enhancement" di simmetria globale. Congetturiamo l'esistenza di tali punti fissi IR e discutiamo delle dualità 3d fornendo controlli espliciti delle funzioni di partizione calcolate tramite localizzazione supersimmetrica. Infine, otteniamo risultati simili per teorie con superpotenziali a potenza per il campo tensoriale antisimmetrico e per teorie confinanti con 6 fondamentali.
This thesis focuses on various non-perturbative aspects of supersymmetric gauge theories in dimensions 2,3 and 4 and several constructions that relate properties of superconformal quantum field theories among different dimensionalities. Various techniques have been applied the most prominent of them being dimensional reduction and compactifications with decorations of the internal manifolds. The thesis deals with two main topics; the first is the study of compactifications of 4d superconformal field theories placed on a Riemann surface with a particular choice of background data along the internal dimensions, the choice of which is imposed by the requirement that supersymmetry is unbroken by the curved geometry. An extensive analysis of this construction is carried out at the formal level for any genus both for minimal and extended supersymmetry. The results obtained provide a systematic classification of all 2d theories that can be constructed via this technique. We then apply the results to the study of several specific 4d models. By restricting to a special class of theories endowed with a toric structure on their moduli space we are able to show a direct connection between the toric geometry and the explicit form of the 2d central charge and anomalies. The second topic is the study of circle compactifications of 4d dualities. We consider the reduction of Seiberg duality and its generalizations to SQCD with symplectic gauge group and adjoint plus fundamental matter fields. A remarkable property of these 4d theories, called E7 surprise, carries over to 3d and it is shown to be responsible for the appearance in the infrared theory of a pattern of duality and global symmetry enhancement. We conjecture the existence of such IR fixed points and support our claim of the 3d dualities by providing explicit checks of the 3d partition functions computed via supersymmetric localization. Finally, we obtain similar results for theories with power-law superpotentials for the antisymmetric tensor field as well as confining theories with 6 fundamentals.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Rovai, Antonin. "Emergent geometry from D-Branes." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209425.

Повний текст джерела

Анотація:

In this thesis, we explain and illustrate on several examples how to derive supergravity solutions by computing observables in the corresponding dual, lower-dimensional field theory.

In particular, no a priori knowledge on the gravitational dual is assumed, including its dimensionality. The basic idea to construct the pre-geometric models is to consider the world-volume theory of probe D-branes in the presence of a large number N of higher-dimensional background branes. In the standard decoupling limit, the probes are moving only in the flat directions parallel to the background D-branes. We show however that the quantum effective action of the probe world-volume theory, obtained at large $N$ using standard vector model techniques, has the required field content to be interpreted as the action describing the probes in a higher-dimensional, curved and classical spacetime. The properties of the emerging supergravity solution are easily found by comparing the quantum effective action of the pre-geometric model with the non-abelian D-brane action. In all the examples we consider, this allows us to derive the metric, the dilaton and various form fields, overall performing exclusively field theoretic computations.

The first part of the thesis consists of introductory chapters, where we review vector models at large N, aspects of brane physics in supergravity and string theory and the gauge/gravity correspondence. The second part contains the original contributions of this thesis, consisting of various explicit emergent geometry examples.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Wens, Vincent. "Of N=1 supersymmetric gauge theories and localization." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210272.

Повний текст джерела

Анотація:

In this thesis, we study certain non-perturbative aspects of N=1 gauge theories. We show how to compute the expectation values of chiral operators (i.e. those that preserve the anti-chiral supercharges) exactly from a first-principle approach based on the path integral over the microscopic fields.

The text is divided into two parts. The first one consists of an original introduction to the tools that underlie the researches and results obtained during this thesis. After a general introduction, we present some methods to obtain exact results. Covered topics include instantons, N=2 supersymmetry and localization,N=1 supersymmetry and holomorphy, and finally the Dijgraaf-Vafa matrix model formalism and the perturbative generalized Konishi anomaly equations. These preliminaries were chosen to enlighten the presentation of our results. A brief overview of our results is then. This includes localization in some N=1 gauge theories, its applications to the computation of chiral correlators as well as a non-perturbative discussion of the generalized Konishi equations and of the Dijkgraaf-Vafa glueball superpotential. We insist on the ideas and the results, postponing the details for the second part, which consists of a faithful reproduction of the papers published during this thesis and in which the author has been involved. /

Dans cette thèse, nous étudions certains aspects non-perturbatifs des théories de jauge supersymétriques N=1. Plus précisemment, nous montrons comment les valeurs moyennes des opérateurs chiraux (qui préservent la moitié des supercharges) dans les vides quantiques peuvent être calculées sans approximations, à partir d'une approche basée sur l'intégrale fonctionnelle sur les champs microscopiques.

Ce mémoire est divisé en deux parties. La première consiste en une introduction à l'approche microscopique des théories de jauge supersymétriques. Une grande fraction de celle-ci est dédiée à la présentation des concepts et méthodes qui sont à la base du développement de ce formalisme et de nos recherches. Ceci inclut les instantons, la supersymétrie N=2 et la localisation dans l'intégrale fonctionnelle, la supersymétrie N=1 et l'holomorphie, et enfin l'approche de Dijkgraaf-Vafa basée sur un modèle de matrices et les équations d'anomalie généralisées de Konishi. Ensuite, nous présentons le formalisme microscopique et les résultats obtenus durant cette thèse. Nous expliquons comment utiliser la technique de localisation dans certaines théories de jauge N=1 et comment l'appliquer au calcul des valeurs moyennes des opérateurs chiraux. Nous discutons également de façon non-perturbative les équations d'anomalie généralisées de Konishi et le superpotentiel de Dijkgraaf-Vafa. La plupart des résultats exacts connus dans les théories de jauge N=1 sont reproduits, dont la condensation des gluinos et la brisure de la symétrie chirale.

Nous insistons sur les idées et les résultats plutôt que sur les détails techniques. Ceux-ci sont décrits dans la seconde partie de ce mémoire, qui consiste en une reproduction fidèle des travaux publiés durant cette thèse.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Lehum, André Carlos. "Quebra de simetria de calibre no modelo de Chern-Simons supersimétrico." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-09052008-102010/.

Повний текст джерела

Анотація:

Através do formalismo de supercampos, estudamos as propriedades ultravioletas da eletrodinâmica quântica supersimétrica no espaço-tempo tridimensional. Mostramos que esta teoria é finita em todas as ordens de perturbação num calibre particular. Também apresentamos uma análise perturbativa do modelo de Chern-Simons supersimétrico acoplado a um supercampo escalar complexo. Com isso, estudamos a quebra da simetria de calibre U(1) e calculamos as primeiras correções quânticas à ação efetiva na fase quebrada. Mostramos que a renormalização da equação de gap é suficiente para assegurar a renormalizabilidade do modelo em um laço de aproximação. Nós também verificamos que quando acoplado a um supercampo escalar sem massa, o modelo de Chern-Simons supersimétrico apresenta geração dinâmica de massa, um mecanismo que em D = 2 + 1 dimensões do espaço-tempo, diferentemente do modelo não-supersimétrico quadridimensional (Coleman- Weinberg), só ocorre a partir da aproximação de dois laços. Alguns outros resultados relacionados são também incluídos nesta tese, tais como um estudo do modelo CP**(N-1) não-comutativo supersimétrico e a equivalência entre os modelos de Maxwell-Chern-Simons e Auto-Dual supersimétricos. Em todo nosso trabalho, supersimetria é manifesta.
Within the superfield formalism, we study the ultraviolet properties of the three-dimensional supersymmetric quantum electrodynamics. The theory is shown to be finite at all loops orders in a particular gauge. We also present a perturbative analysis of the supersymmetric Chern-Simons model coupled to a Higgs field. We study the spontaneous symmetry breaking of the U(1) gauge symmetry and evaluate the first quantum corrections to the effective action in the broken phase. We show that the infinite renormalization of the gap equation is enough to ensure the renormalizability of the model at the first loop level. We also verify that when coupled to a massless scalar superfield, the supersymmetric Chern-Simons model present dynamical generation of mass, a mechanism that in D = 2 + 1 spacetime dimensions, differently from the four-dimensional non-supersymetric model (Coleman-Weinberg), only occurs from two-loop order. Some other related results are also enclosed in this thesis, such as a study of the supersymmetric noncommutative CP**(N-1) model and the equivalence between Maxwell-Chern-Simons and Self-Dual supersymmetric models. In whole work, supersymmetry is manifest.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Pupasov, Andrey. "Investigation of the dynamics of physical systems by supersymmetric quantum mechanics." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210128.

Повний текст джерела

Анотація:

Relations between propagators and Green

functions of Hamiltonians which are SUSY partners have been obtained. New exact propagators for the family of multi-well, time-dependent and non-hermitian potentials have been calculated.

Non-conservative SUSY transformation has been studied in

the case of multichannel Schrodinger equation with different thresholds. Spectrum (bound/virtual states and resonances) of the

non-conservative SUSY partner of zero potential has been founded.

Exactly solvable model of the magnetic induced Feshbach resonance

has been constructed. This model was tested in the case of Rb$^{85}$.

Conservative SUSY transformations of the first and the second order have been studied in the case of multichannel Schrodinger equation with equal thresholds. Transformations which introduce non-trivial coupling between scattering channels have been founded.

The first order SUSY transformation which preserves $S$-matrix eigen-phase shifts and

modifies mixing parameter has been founded in the case of two channel scattering with partial waves of different parities. In the case of coinciding parities we have found the second order SUSY transformation which preserves $S$-matrix eigen-phase shifts and modifies mixing parameter.

Phenomenological two channel $^3S_1-^3D_1$

neutron-proton potential has been obtained by using single channel, phase equivalent and coupling SUSY transformations applied to zero potential.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Gauge Theory, Supergravity, Supersymmetry"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями