| Popis: |
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. |
