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Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / In this thesis we present a comprehensive study of perturbative and non-perturbative non-Abelian gauge theories in the light of gauge-fixing procedures, focusing our attention on the BRST formalism in Yang-Mills theory. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1284180 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2007

Bibliography : leaves 117-120 / vi, 120 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1992

Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / In this thesis we present a comprehensive study of perturbative and non-perturbative non-Abelian gauge theories in the light of gauge-fixing procedures, focusing our attention on the BRST formalism in Yang-Mills theory. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1284180 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2007

Thesis (Ph. D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1992. / Includes bibliographical references (p. 105-111).

In this thesis we study two classes of backgrounds in Typo IIB supergravity which admit interpretation in terms of dual N = 1 Supersymmetric Field Theories. The first is obtained by wrapping D5 branes on a two-cycle inside the conifold; the second is the class containing the dual to the baryonic branch of Klebanov-Strassler. These backgrounds are related via a 'solution generating procedure' (or rotation) and have a number of interesting properties. First, we study non-Supersymmetric deformations of the baryonic branch by making use of the rotation procedure. We interpret these deformations as soft-breaking through the addition of gaugino masses, and calculate various observables which support this picture. We then explore the two-dimensional solution space of supergravity solutions associated with these deformations, finding a number of interesting limiting cases. We see that much of the structure of the Supersymmetric baryonic branch survives, even for large values of the deformation. Second, we study probe-D7 branes which wrap an internal three-dimensional manifold and lie at the equator of the transverse two-sphere, in the class of wrapped D5 brane backgrounds. We employ this method to model Chiral-symmetry breaking and present a simple diagnostic tool for determining the classical stability of such embeddings, in particular cases we find that a new type of phase transition appears, putting limits on the region of parameter space which can be used to study physics of the dual field theory. Finally, we study the relationship between confinement in a Quantum Field Theory and the presence of a first-order phase transition in its Entanglement Entropy. We determine the sufficient conditions for such a phase transition and compare to the conditions on a Rectangular Wilson Loop to probe confinement. In certain backgrounds with non-local high energy behaviour, we show that new configurations (associated with the introduction of a UV cutoff) are required in order to recover the otherwise absent phase transition. We also show that a local UV-completion, obtained using the rotation procedure, to the non-local theories has a similar effect to the cutoff.

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Cette thèse s'inscrit dans le cadre de la physique mathématique des interactions fondamentales. Elle porte sur l'étude des théories de champs qui décrivent les particules élémentaires. En particulier, les théories de champs de spin élevé (plus grand ou égal à 2) sont analysées. Mis à part pour le graviton, vecteur supposé des interactions gravitationnelles, il n'y a aucun indice que ces champs soient présents dans la nature. Cependant leur existence n'est pas impossible théoriquemement et ils interviennent dans la théorie des cordes, candidate pour une théorie quantique d'unification de toutes les forces fondamentales y compris la gravitation. En effet, les modes de vibration de la corde élémentaire sont décrits par des champs de spin élevé.   Dans ce travail, la dimension de l'espace-temps est laissée arbitraire, ce qui entraine la possibilité d'avoir plusieurs sortes (= représentations) de champs différentes ayant le même spin. Le premier aspect traité dans cette thèse concerne les dualités, symétries qui relient entre elles plusieurs théories. Il est montré que différentes représentations de champs de spin élevé sont duales au niveau de l'action. En particulier, en dimension quatre, la dualité échange la composante électrique et la composante magnétique d'un même champs. Cette propriété est ensuite utilisée pour introduire des sources magnétiques pour les champs de spin élevé. La construction généralise les travaux de Dirac sur le couplage au champ électromagnétique de monopoles magnétiques. Une condition de quantification est également dérivée pour des quantités conservées, qui généralise la condition de quantification de Dirac pour la charge électrique en présence de monopoles magnétiques. La deuxième partie de la thèse est consacrée aux interactions de champs de spin élevé. L'analyse est effectuée dans le formalisme de champs et d'antichamps dévelopé par Batalin et Vilkovsky. Elle repose sur la procédure de déformation de l'équation maîtresse mise au point par Henneaux et Barnich. Les champs étudiés sont les champs de spin deux exotiques (c-à-d différents du graviton) ainsi que les champs de spin trois complètement symétriques. Pour les premiers, il est prouvé que toutes les interactions doivent être abélienne. Il n'y a donc pas d'équivalent de la théorie d'Einstein pour ces champs. Dans le cas des champs de spin trois, plusieurs vertex cohérents au premier ordre sont obtenus. <br> In this thesis, we consider two aspects of higher-spin gauge field theories: dualities and interactions. The first aspect is related to the presence of dualities, i.e., 'hidden' symmetries among gauge field theories. Do two higher-spin theories corresponding to different irreducible representations of the Poincaré group have the same physical content. Duality relations were already known at the level of the equations of motion and Bianchi identities, here we prove (in some cases) that these dualities hold also at the level of the action. As a consequence, the dual theories are formally equivalent. For example, in five space-time dimensions the spin-two theory of Pauli and Fierz is dual to the theory of a mixed-symmetry spin-two field written by Curtright. In four space-time dimensions the duality exchanges the electric and magnetic degrees of freedom of the field. This property leads us to introduce external magnetic sources for higher-spin fields, thereby generalizing to arbitrary spin the work of Dirac on the coupling of magnetic monopoles to the electromagnetic field. Similarly to the quantization condition on the product of the electric and magnetic charges for electromagnetism, there is a quantization condition on the product of conserved ``electric' and ``magnetic' charges for higher spins. The second aspect of higher-spin gauge field theories that is analysed in this thesis is the problem of interactions. Self-interactions of exotic spin-two gauge fields are studied, as well as self-interactions of completely symmetric spin-three fields. This is done in the BRST field-antifield formalism developped by Batalin and Vilkovisky, using the technique of consistent deformations of the master equation proposed by Barnich and Henneaux.