相关论文: On the YM and QCD spectra from five dimensional st…

We introduce a simple method to extract the representation content of the spectrum of a system with SU(2) symmetry from its partition function. The method is easily generalized to systems with SO(2,4) symmetry, such as conformal field…

We propose a holographic dual of large N_c QCD with the gauge group O(N_c) and USp(N_c) and N_f flavors of massless quarks. This is constructed by adding O6-planes to an intersecting D4-D8 system in type IIA superstring theory. The…

We consider quintessence models within 4D effective descriptions of gravity coupled to two scalar fields. These theories are known to give rise to viable models of late-time cosmic acceleration without any need for flat potentials, and so…

N=1 supersymmetric QCD is considered using the recently proposed picture of it as the world volume theory of a single M-theory fivebrane with two of its dimensions wrapped on a Riemann surface. The conditions under which a second M-theory…

We consider an instance of the AdS/CFT duality where the bulk theory contains an open string tachyon, and study the instability from the viewpoint of the boundary field theory. We focus on the specific example of the AdS_5 X S^5 background…

We study N=1 four dimensional gauge theories as the world volume theory of D4-branes between NS 5-branes. We find constructions for a number of known field theory dualities involving $SU(N_c)\times SU(N_c')$ groups, coupled by matter fields…

Lattice studies indicate existence of magnetic strings in QCD vacuum. We argue that recently found nonabelian strings with rich worldsheet dynamics provide a proper pattern for the strings observed on the lattice. In particular, within this…

We study five dimensional non critical type 0 string theory and its correspondence to non supersymmetric Yang Mills theory in four dimensions. We solve the equations of motion of the low energy effective action and identify a class of…

We consider heterotic strings on a warped Eguchi-Hanson space with five-brane and line bundle gauge fluxes. The heterotic string admits an exact CFT description in terms of an asymmetrically gauged SU(2)xSL(2,R) WZW model, in a specific…

In these lecture notes from the 2002 Cargese summer school we review the progress that has been made towards finding a string theory for QCD (or for pure (super)Yang-Mills theory) following the discovery of the AdS/CFT correspondence. We…

1. Preliminaries. 2. Heterotic string and motivations for large volume compactifications; 2.1 Gauge coupling unification; 2.2 Supersymmetry breaking by compactification. 3. M-theory on S^1/Z_2 \times Calabi-Yau. 4. Type I/I' string theory…

By studying 2d string compactifications with half-maximal supersymmetry in a variety of duality frames, we find a natural physical setting for understanding Umbral moonshine. Near points in moduli space with enhanced gauge symmetry, we find…

A system of k Neveu-Schwarz (NS) 5-branes of type II string theory with one transverse direction compactified on a circle admits various unstable D-brane systems, - some with geometric instability arising out of being placed at a point of…

We study two dimensional $N=(4,4)$ supersymmetric gauge theories with various gauge groups and various hypermultiplets in the fundamental as well as bi-fundamental and adjoint representations. They have " mirror theories " which become…

Taking advantage of the equivalence between supersymmetric Yang-Mills theory on non-commutative spaces and the field theory limit of D3-branes in the background of NSNS 2-form field, we investigate the static properties of magnetic…

We find solutions of 11-dimensional supergravity for M5-branes wrapped on Riemann surfaces. These solutions preserve ${\cal N} = 2$ four-dimensional supersymmetry. They are dual to ${\cal N} = 2$ gauge theories, including non-conformal…

I review the calculation of the glueball spectrum in non-supersymmetric Yang-Mills theory (in 3 and 4 dimensions) using the conjectured duality between supergravity and large N gauge theories. The glueball masses are obtained by solving the…

We explore the string spectrum in the Witten QCD model by considering classical string configurations, thereby obtaining energy formulas for quantum states with large excitation quantum numbers representing glueballs and Kaluza-Klein…

This thesis investigates correspondences between open and closed strings. This is done on the level of coupled open-closed moduli spaces and from a string field theoretic point of view. The construction of boundary string field theory on…

We identify the 4D field theories living on the world volume of D4 branes in non-supersymmetric type IIA string theory constructions. They are softly broken N=2 SQCD with the breakings introduced through vevs of the auxilliary fields in the…