We study N = 1 four dimensional gauge theories as the world volume theory of D4branes between NS 5-branes. We find constructions for a number of known field theory dualities involving SU (N c ) × SU (N ′ c ) groups, coupled by matter fields F in the (N c ,N c ) representation, in terms of branes of type IIA string theory. The dual gauge group follows from simply reversing the ordering of the NS 5-branes and the D6-branes while conserving magnetic charge on the world volume of the branes. We interpret many field theory phenomena such as deformation of the superpotential W = Tr (F F ) k+1 in terms of the position of branes. By looking to D-branes for guidance, we find new N = 1 dualities involving arbitrary numbers of gauge groups. We propose a mechanism for enhanced chiral symmetry in the brane construction which, we conjecture, is associated with tensionless threebranes in six dimensions. 4/97

No abstract

We discuss SU (N c ) gauge theory coupled to two adjoint chiral superfields X and Y , and

We investigate the low energy dynamics of N = 1 supersymmetric SO(N ) gauge theories with a single symmetric tensor matter field. These theories exhibit non-trivial matching of global 't Hooft anomalies at the origin of moduli space. We argue that their quantum moduli spaces possess distinct Higgs and confining branches which touch at the origin in an interacting non-Abelian Coulomb phase. The matching of anomalies between microscopic degrees of freedom and colorless moduli therefore appears to be coincidental.We discuss a formal mathematical relation between the SO(N ) model and an analogous Sp(2N ) theory with a single antisymmetric matter field which provides an explanation for the anomaly matching coincidence. 2/98

In this paper we show how two dimensional electron systems can be modeled by strings interacting with D-branes. The dualities of string theory allow several descriptions of the system. These include descriptions in terms of solitons in the near horizon D6-brane theory, non-commutative gauge theory on a D2-brane, the Matrix Theory of D0-branes and finally as a giant graviton in M-theory. The soliton can be described as a D2-brane with an incompressible fluid of D0-branes and charged string-ends moving on it. Including an N S5 brane in the system allows for the existence of an edge with the characteristic massless chiral edge states of the Quantum Hall system.