Gravity duals of supersymmetric gauge theories on three-manifolds

We study gravity duals to a broad class of N=2 supersymmetric gauge theories defined on a general class of three-manifold geometries. The gravity backgrounds are based on Euclidean self-dual solutions to four-dimensional gauged supergravity. As well as constructing new examples, we prove in general that for solutions defined on the four-ball the gravitational free energy depends only on the supersymmetric Killing vector, finding a simple closed formula when the solution has U(1) x U(1) symmetry. Our result agrees with the large N limit of the free energy of the dual gauge theory, computed using localization. This constitutes an exact check of the gauge/gravity correspondence for a very broad class of gauge theories with a large N limit, defined on a general class of background three-manifold geometries.Comment: 74 pages, 2 figures; v2: minor change

Scalar geometry and masses in Calabi-Yau string models

We study the geometry of the scalar manifolds emerging in the no-scale sector of Kahler moduli and matter fields in generic Calabi-Yau string compactifications, and describe its implications on scalar masses. We consider both heterotic and orientifold models and compare their characteristics. We start from a general formula for the Kahler potential as a function of the topological compactification data and study the structure of the curvature tensor. We then determine the conditions for the space to be symmetric and show that whenever this is the case the heterotic and the orientifold models give the same scalar manifold. We finally study the structure of scalar masses in this type of geometries, assuming that a generic superpotential triggers spontaneous supersymmetry breaking. We show in particular that their behavior crucially depends on the parameters controlling the departure of the geometry from the coset situation. We first investigate the average sGoldstino mass in the hidden sector and its sign, and study the implications on vacuum metastability and the mass of the lightest scalar. We next examine the soft scalar masses in the visible sector and their flavor structure, and study the possibility of realizing a mild form of sequestering relying on a global symmetry.Comment: 36 pages, no figure

Wilson loops and their gravity duals in AdS4/CFT3

In the first part of this thesis, we study the duality of Wilson loops and M2-branes in AdS4/CFT3. We focus on supersymmetric M-theory solutions on AdS4xY7 that have a superconformal dual description on S3 &amp;equals; ∂AdS4. We will find that the Hamiltonian function hM for the M-theory circle plays an important role in the duality. We show that an M2-brane wrapping the M-theory circle is supersymmetric precisely at the critical points of hM, and moreover the value of this function at those points determines the M2-brane actions. Such a configuration determines the holographic dual of a Wilson loop for a Hopf circle in S3. We find agreement in large classes of examples between the Wilson loop and its dual M2-brane and also that the image hM(Y7) determines the range of support of the eigenvalues in the dual large N matrix model, with the critical points of hM mapping to points where the derivative of the eigenvalue density is discontinuous. We will then move away from the three-sphere and construct gravity duals to a broad class of N&amp;equals;2 supersymmetric gauge theories defined on a general class of three-manifold geometries. The gravity backgrounds are based on Euclidean self-dual solutions to four-dimensional gauged supergravity. As well as constructing new examples, we prove in general that for solutions defined on the four-ball the gravitational free energy depends only on the supersymmetric Killing vector. Our result agrees with the large N limit of the free energy of the dual gauge theory, computed using localisation. This constitutes an exact check of the gauge/gravity correspondence for a very broad class of gauge theories defined on a general class of background three-manifold geometries. To further verify that our gravitational backgrounds are indeed dual to field theories on their boundaries, we compute Wilson loops and their M2-brane duals in this general setting. We find that the Wilson loop is given by a simple closed formula which depends on the background geometry only through the supersymmetric Killing vector field. The supergravity dual M2-brane precisely reproduces this large N field theory result. This constitutes a further check of AdS4/CFT3 for a very broad class of examples.</p

Wilson loops and their gravity duals in AdS_4/CFT_3

In the first part of this thesis, we study the duality of Wilson loops and M2-branes in AdS4/CFT3. We focus on supersymmetric M-theory solutions on AdS4xY7 that have a superconformal dual description on S3 &equals; &#8706;AdS4. We will find that the Hamiltonian function hM for the M-theory circle plays an important role in the duality. We show that an M2-brane wrapping the M-theory circle is supersymmetric precisely at the critical points of hM, and moreover the value of this function at those points determines the M2-brane actions. Such a configuration determines the holographic dual of a Wilson loop for a Hopf circle in S3. We find agreement in large classes of examples between the Wilson loop and its dual M2-brane and also that the image hM(Y7) determines the range of support of the eigenvalues in the dual large N matrix model, with the critical points of hM mapping to points where the derivative of the eigenvalue density is discontinuous. We will then move away from the three-sphere and construct gravity duals to a broad class of N&equals;2 supersymmetric gauge theories defined on a general class of three-manifold geometries. The gravity backgrounds are based on Euclidean self-dual solutions to four-dimensional gauged supergravity. As well as constructing new examples, we prove in general that for solutions defined on the four-ball the gravitational free energy depends only on the supersymmetric Killing vector. Our result agrees with the large N limit of the free energy of the dual gauge theory, computed using localisation. This constitutes an exact check of the gauge/gravity correspondence for a very broad class of gauge theories defined on a general class of background three-manifold geometries. To further verify that our gravitational backgrounds are indeed dual to field theories on their boundaries, we compute Wilson loops and their M2-brane duals in this general setting. We find that the Wilson loop is given by a simple closed formula which depends on the background geometry only through the supersymmetric Killing vector field. The supergravity dual M2-brane precisely reproduces this large N field theory result. This constitutes a further check of AdS4/CFT3 for a very broad class of examples.This thesis is not currently available via ORA

Decreased heat-labile opsonic activity and complement levels associated with evidence of C3 breakdown products in infected pleural effusions

Heat-labile opsonic activity was measured simultaneously in serum and pleural fluid of patients with transudates, infectious exudates (with positive or negative bacterial culture) and neoplastic exudates, using two different complement-dependent phagocytic tests: the killing of Staphylococcus aureus Wood 46 variant strain (K50 opsonic titers) and the assessment of ingestion rate of endotoxin-coated paraffin particles (Oil Red 0 uptake test). K50 opsonic titers were lower in culture-positive pleural effusions as compared to culture-negative (P < 0.002) or neoplastic effusions (P < 0.002). These results were corroborated by the Oil Red 0 uptake test. The data obtained with the two assays showed a significant correlation (P < 0.001). The hemolytic activity of complement (CH50) as well as the levels of C3 breakdown product, C3d, were measured in the same sera and pleural fluid samples and in an additional group of patients with pleural effusions of the same etiology. Effusions with positive cultures showed lower CH50 values (P < 0.01) and higher C3d values (P < 0.05) when compared to culture-negative pleural fluids. Finally, evidence for immune complexes in pleural effusions and sera was looked for by determination of Clq binding activity. Levels were higher in culture-positive effusions when compared to culture-negative fluids (P = 0.005).K50 opsonic titers showed a positive correlation with CH50 values (P < 0.001) for all fluids tested. Similarly Clq binding activity correlated with C3d levels in effusions of infectious origin (P = 0.05). Recovery experiments using the various bacterial species isolated from culture-positive pleural effusions showed evidence of complement inactivation upon incubation with pooled sera at concentrations of 10(7)-10(8) microorganisms/ml. These results indicate that one important reason for bacterial persistence in empyema may be decreased opsonization secondary to local consumption of complement