  We describe duality cascades and their infrared behavior for systems of
D3-branes at singularities given by complex cones over del Pezzo surfaces (and
related examples), in the presence of fractional branes. From the gauge field
theory viewpoint, we show that D3-branes probing the infrared theory have a
quantum deformed moduli space, given by a complex deformation of the initial
geometry to a simpler one. This implies that for the dual supergravity
viewpoint, the gauge theory strong infrared dynamics smoothes out the naked
singularities of the recently constructed warped throat solutions with 3-form
fluxes, describing the cascading RG flow of the gauge theory. This behavior
thus generalizes the Klebanov-Strassler deformation of the conifold. We
describe several explicit examples, including models with several scales of
strong gauge dynamics. In the regime of widely separated scales, the dual
supergravity solutions should correspond to throats with several radial regions
with different exponential warp factors. These rich throat geometries are
expected to have interesting applications in compactification and model
building. Along our studies, we also construct explicit duality cascades for
gauge theories with irrational R-charges, obtained from D-branes probing
complex cones over dP1 and dP2.
