On the gravity dual of Chern-Simons-matter theories with unquenched flavor

We find solutions of type IIA supergravity which are dual to three-dimensional Chern-Simons-matter theories with unquenched fields in the fundamental representation of the gauge group (flavors). In the holographic dual the addition of flavor is performed by means of D6-branes that are extended along the Minkowski gauge theory directions and are delocalized in the internal space in such a way that the system is N=1 supersymmetric and the flavor group is abelian. For massless flavors the corresponding geometry has the form of a product space AdS_4x M_6, where M_6 is a six-dimensional compact manifold whose metric is obtained by squashing the Fubini-Study metric of CP^3 with suitable constant factors which depend on the number of flavors. We compute the effect of dynamical quarks in several observables and, in some cases, we compare our results with the ones corresponding to the N=3 supergravity solutions generated by localized flavor branes. We also show how to generalize our results to include massive flavors.