BPS Partition Functions for Quiver Gauge Theories: Counting Fermionic Operators

We discuss a general procedure to obtain 1/2 BPS partition functions for generic N=1 quiver gauge theories. These functions count the gauge invariant operators (bosonic and fermionic), charged under all the global symmetries (mesonic and baryonic), in the chiral ring of a given quiver gauge theory. In particular we discuss the inclusion of the spinor degrees of freedom in the partition functions.Comment: 30 page

Operators and vacua of N=1 field theories

We review the idea of Hilbert Series as a tool to study the moduli space and the BPS operators of four dimensional N=1 supersymmetric field theories. We concentrate on the particular case of N=1 superconformal field theories living on N D3 branes at toric Calabi-Yau singularities. The main claim is: it is possible to write down explicit partition functions counting all the local BPS operators for generic N number of branes, and obtain important informations about the BPS operators, the moduli space and the dual geometry.Comment: 10 pages, 1 figure. To appear in Nuovo Cimento B for the Premio Nazionale "Sergio Fubini" 2008, CNS4 meeting INFN, 21 Sep 2009, Rome, Ital

Spin(7) duality for N=1 CS-matter theories

In this paper we propose a duality for non-holomorphic N=1 CS-matter theories living on M2 branes probing Spin(7) cones. We call this duality Spin(7) duality. Two theories are named Spin(7) dual if they have the same moduli space: a real Spin(7) cone with base a weak G_2 manifold, and they are hence holographic dual to the same AdS_4 x G_2 M theory solution. We provide a systematic way to generate these dualities, derived by combining toric duality for N=2 CS-matter theories and generalized non-holomorphic orientifold projections to N=1. Brane construction, AdS/CFT correspondence, and the computation of the moduli space support our proposal at the classical level and provide some arguments at the quantum strong coupling regime. The relation with Seiberg-like duality is also analyzed.Comment: 37 pages, 3 figure

Non-supersymmetric CS-matter theories with known AdS duals

We consider three dimensional conformal field theories living on a stack of N anti-M2 branes at the tip of eight-dimensional supersymmetric cones. The corresponding supergravity solution is obtained by changing sign to the four-form in the Freund-Rubin solution representing M2 branes ("skew-whiffing" transformation) and it is known to be stable. The existence of these non supersymmetric, stable field theories, at least in the large N limit, is a peculiarity of the AdS4/CFT3 correspondence with respect to the usual AdS5/CFT4, and it is worthwhile to study it. We analyze in detail the KK spectrum of the skew-whiffed solution associated with S^7/Z_k and we speculate on the natural field content for a candidate non-supersymmetric dual field theory.Comment: 16 pages; Contribution prepared for the AHEP special issue on "Computational Algebraic Geometry in String and Gauge Theory", citations adde

Electromagnetic response of strongly coupled plasmas

We present a thorough analysis of the electromagnetic response of strongly coupled neutral plasmas described by the gauge/gravity correspondence. The coupling of the external electromagnetic field with the tower of quasi-normal modes of the plasmas supports the presence of various electromagnetic modes with different properties. Among them we underline the existence of negative refraction with low dissipation for a transverse non-hydrodynamical mode. Previous hydrodynamical approaches have shown the ubiquitous character of negative refraction in charged plasmas and the absence thereof in neutral plasmas. Our results here extend the analysis for neutral plasmas beyond the hydrodynamical regime. As an application of these new insights we briefly discuss the case of the quark gluon plasma in the temperature dominated regime.Comment: 29 pages, 15 figure

Master Space and Hilbert Series for N=1 Field Theories

Master Space and Hilbert Series are general tools to study any N=1 supersymmetric field theory. We concentrate on the particular case of N=1 super conformal field theories living on D3 branes at toric Calabi Yau singularities. We start reviewing the topic of branes at singularities, their algebraic geometric and field theory description. We then study the complete moduli spaces for N=1 and generic N number of branes, their different branches, their geometric properties and their symmetries. We study the spectrum of BPS operators both mesonic and baryonic, for N=1 and generic N number of branes, in the field theory and in the dual gravity side and the map between the two. More topics like the study of fermionic BPS operators, the modification of the moduli spaces and the chiral rings under marginal deformations and Seiberg Duality, are also briefly discussed. This paper is a revised version of the author's PhD thesis and it is aimed to give a pedagogical introduction to the use of Master Space and Hilbert Series to investigate supersymmetric field theories.Comment: 231 pages, PhD thesi

Counting BPS Baryonic Operators in CFTs with Sasaki-Einstein duals

We study supersymmetric D3 brane configurations wrapping internal cycles of type II backgrounds AdS(5) x H for a generic Sasaki-Einstein manifold H. These configurations correspond to BPS baryonic operators in the dual quiver gauge theory. In each sector with given baryonic charge, we write explicit partition functions counting all the BPS operators according to their flavor and R-charge. We also show how to extract geometrical information about H from the partition functions; in particular, we give general formulae for computing volumes of three cycles in H.Comment: 46 pages, 10 figures; comments and clarifications added, published versio

Electromagnetic properties of viscous charged fluids

We provide a general theoretical framework to describe the electromagnetic properties of viscous charged fluids, consisting for example of electrons in certain solids or plasmas. We confirm that finite viscosity leads to multiple modes of evanescent electromagnetic waves at a given frequency, one of which is characterized by a negative index of refraction, as previously discussed in a simplified model by one of the authors. In particular we explain how optical spectroscopy can be used to probe the viscosity. We concentrate on the impact of this on the coefficients of refraction and reflection at the sample-vacuum interface. Analytical expressions are obtained relating the viscosity parameter to the reflection and transmission coefficients of light. We demonstrate that finite viscosity has the effect to decrease the reflectivity of a metallic surface, while the electromagnetic field penetrates more deeply. While on a phenomenological level there are similarities to the anomalous skin effect, the model presented here requires no particular assumptions regarding the corpuscular nature of the charge liquid. A striking consequence of the branching phenomenon into two degenerate modes is the occurrence in a half-infinite sample of oscillations of the electromagnetic field intensity as a function of distance from the interface.Comment: 12 pages, 5 figure

4D/3D reduction of dualities: mirrors on the circle

We engineer a brane picture for the reduction of Seiberg dualities from 4D to 3D, valid also in the presence of orientifold planes. We obtain effective 3D dualities on the circle by T-duality, geometrizing the non-perturbative superpotential which is an affine Toda potential. When reducing to pure 3D, we define a double-scaling limit which creates a confining sector, giving a unified mechanism for the brane reduction of dualities.Comment: 27 pages, 16 figures, discussion improve