Geometry, D-branes and N=1 duality in four dimensions. II

We study N=1 dualities in four dimensional supersymmetric gauge theories in terms of wrapping D 6-branes around 3-cycles of Calabi-Yau threefolds in type IIA string theory. We generalize the recent work of geometrical realization for the models which have the superpotential corresponding to an Ak type singularity, to various models presented by Brodie and Strassler, consisting of Dk+2 superpotential of the form W=TrXk+1+TrXY2. We discuss a large number of representations for the field Y, but with X always in the adjoint (symmetric) [antisymmetric] representation for SU(SO)[Sp] gauge groups.