Recently, a D–brane construction in type IIA string theory was shown to yield the electric/magnetic duality of four dimensional N=1 supersymmetric U(Nc) gauge theories with Nf flavours of quark. We present here an extension of that construction which yields the electric/magnetic duality for the SO(Nc) and USp(Nc) gauge theories with Nf quarks, by adding an orientifold plane which is consistent ...

In this talk I describe the low energy effective theory of the (supersymmetric) Randall-Sundrum scenario with arbitrary brane tensions. The distance between the branes is stabilized, at the classical level, by a potential for the radion field. In the supersymmetric case, supersymmetry can be broken by a VEV for the fifth-component of the graviphoton.

We compute the large N limit of Wilson loop expectation values for a broad class of N = 2 supersymmetric gauge theories defined on a general class of background three-manifolds M3, diffeomorphic to S 3. We find a simple closed formula which depends on the background geometry only through a certain supersymmetric Killing vector field. The supergravity dual of such a Wilson loop is an M2-brane wr...

We study the four-dimensional gauge theories which are associated with classical vacua of the type II superstring, i.e. which correspond to a superconformal field theory on the world sheet. Using the fact that gauge symmetry arises from a supersymmetric affine Kac-Moody algebra, and demanding unitarity of the underlying world-sheet field theory, we show that no such vacua can yield the particle...

We propose a large N dual of 4d, N = 1 supersymmetric, SU(N) Yang-Mills with adjoint field Φ and arbitrary superpotential W (Φ). The field theory is geometrically engineered via D-branes partially wrapped over certain cycles of a non-trivial Calabi-Yau geometry. The large N , or low-energy, dual arises from a geometric transition of the Calabi-Yau, where the branes have disappeared and have bee...

The concept of supersymmetry arose in the study of elementary particle physics. The term “supersymmetry” was originally used in reference to the symmetry of bosons and fermions, which behave according to different statistical laws. Supersymmetry is widely regarded as a necessary concept for unifying all the elementary forces. The concept of supersymmetry was originally formulated in the framewo...

Majumder and Sen have given an explicit construction of a first order phase transition in a non–supersymmetric system of Dbranes that occurs when the B field is varied. We show that the description of this transition in terms of K-theory involves a bundle of K groups of non–commutative algebras over the Kähler cone with nontrivial monodromy. Thus the study of monodromy in K groups associated wi...