http://inspirehep.net/record/499969/files/arXiv:hep-th_9905111.pdf

Large N Field Theories, String Theory and Gravity

The correspondence between supergravity (and string theory) on AdS space and boundary conformal eld theory relates the thermodynamics of N = 4 super Yang-Mills theory in four dimensions to the thermodynamics of Schwarzschild black holes in Anti-de Sitter space. In this description, quantum phenomena such as the spontaneous breaking of the center of the gauge group, magnetic connement, and the mass gap are coded in classical geometry. The correspondence makes it manifest that the entropy of a very large AdS Schwarzschild black hole must scale \holographically" with the volume of its horizon. By similar methods, one can also make a speculative proposal for the description of large N gauge theories in four dimensions without supersymmetry.

https://www.intlpress.com/site/pub/files/_fulltext/journals/atmp/1998/0002/0003/ATMP-1998-0002-0003-a003.pdf

Anti-de Sitter Space, Thermal Phase Transition, And Confinement in Gauge Theories

http://cds.cern.ch/record/359584/files/9807080.pdf

Superconformal field theory on threebranes at a Calabi-Yau singularity

The correspondence between supergravity (and string theory) on $AdS$ space and boundary conformal field theory relates the thermodynamics of ${\cal N}=4$ super Yang-Mills theory in four dimensions to the thermodynamics of Schwarzschild black holes in Anti-de Sitter space. In this description, quantum phenomena such as the spontaneous breaking of the center of the gauge group, magnetic confinement, and the mass gap are coded in classical geometry. The correspondence makes it manifest that the entropy of a very large $AdS$ Schwarzschild black hole must scale ``holographically'' with the volume of its horizon. By similar methods, one can also make a speculative proposal for the description of large $N$ gauge theories in four dimensions without supersymmetry.

Anti-de Sitter Space, Thermal Phase Transition, And Confinement In Gauge Theories

Massive gravity has seen a resurgence of interest due to recent progress which has overcome its traditional problems, yielding an avenue for addressing important open questions such as the cosmological constant naturalness problem. The possibility of a massive graviton has been studied on and off for the past 70 years. During this time, curiosities such as the van Dam, Veltman, and Zakharov (vDVZ) discontinuity and the Boulware-Deser ghost were uncovered. These results are rederived in a pedagogical manner and the St\"uckelberg formalism to discuss them from the modern effective field theory viewpoint is developed. Recent progress of the last decade is reviewed, including the dissolution of the vDVZ discontinuity via the Vainshtein screening mechanism, the existence of a consistent effective field theory with a stable hierarchy between the graviton mass and the cutoff, and the existence of particular interactions which raise the maximal effective field theory cutoff and remove the ghosts. In addition, some peculiarities of massive gravitons on curved space, novel theories in three dimensions, and examples of the emergence of a massive graviton from extra dimensions and brane worlds are reviewed.

Theoretical Aspects of Massive Gravity

String expansion as large N expansion of gauge theories

In this paper we consider type I string theory compactified on a {bold Z}{sub 7} orbifold. The model has N=1 supersymmetry, a U(4){circle_times}U(4){circle_times}U(4){circle_times}SO(8) gauge group, and chiral matter. There are only D9-branes (for which we discuss tadpole cancellation conditions) in this model corresponding to a perturbative heterotic description in a certain region of the moduli space. We construct the heterotic dual, match the perturbative type I and heterotic tree-level massless spectra via giving certain scalars appropriate vacuum expectation values, VEVs, and point out the crucial role of the perturbative superpotential (on the heterotic side) for this matching. The relevant couplings in this superpotential turn out to be nonrenormalizable (unlike the Z-orbifold case discussed by Kakushadze, where Yukawa couplings sufficed for duality matching). We also discuss the role of the anomalous U(1) gauge symmetry present in both type I and heterotic models. In the perturbative regime we match the (tree-level) moduli spaces of these models. We point out possible generalizations of the {bold Z}{sub 3} and {bold Z}{sub 7} cases to include D5-branes which would help in understanding nonperturbative five-brane dynamics on the heterotic side. {copyright} {ital 1997} {ital The American Physical Society}

/pdf/a-chiral-n-1-type-i-vacuum-in-four-dimensions-and-its-230c7izti8.pdf

A chiral N = 1 type I vacuum in four dimensions and its heterotic dual

Aspects of N = 1 type I-heterotic duality in four dimensions

Type IIB orientifolds, F-theory, Type I strings on orbifolds and Type I-heterotic duality

We consider six dimensional $\mathcal{N}=1$ space-time supersymmetric type IIB orientifolds with a nonzero untwisted NS-NS sector $B$ field. The $B$ field is quantized due to the requirement that the type IIB spectrum be left-right symmetric. The presence of the $B$ field results in rank reduction of both 99 and 55 open string sector gauge groups. We point out that in some of the models with a nonzero $B$ field there are extra tensor multiplets in the ${\mathbf{Z}}_{2}$ twisted closed string sector, and we explain their origin in a simple example. Also, the 59 open string sector states come with a multiplicity that depends on the $B$ field. These two facts are in accord with anomaly cancellation requirements. We point out relations between various orientifolds with and without the $B$ field, and also discuss the F-theory duals of these models.

/pdf/type-iib-orientifolds-with-ns-ns-antisymmetric-tensor-17jq8m0mcu.pdf

Zurab Kakushadze

Papers

String expansion as large N expansion of gauge theories

A chiral N = 1 type I vacuum in four dimensions and its heterotic dual

Aspects of N = 1 type I-heterotic duality in four dimensions

Type IIB orientifolds, F-theory, Type I strings on orbifolds and Type I-heterotic duality

Type IIB orientifolds with NS-NS antisymmetric tensor backgrounds