Type IIA AdS4 compactifications on cosets, interpolations and domain walls

We present a classification of a large class of type IIA N=1 supersymmetric compactifications to AdS4, based on left-invariant SU(3)-structures on coset spaces. In the absence of sources the parameter spaces of all cosets leading to a solution contain regions corresponding to nearly-Kaehler structure. I.e. all these cosets can be viewed as deformations of nearly-Kaehler manifolds. Allowing for (smeared) six-brane/orientifold sources we obtain more possibilities. In the second part of the paper, we use a simple ansatz, which can be applied to all six-dimensional coset manifolds considered here, to construct explicit thick domain wall solutions separating two AdS4 vacua of different radii. We also consider smooth interpolations between AdS4 x M6 and R^{1,2} x M7, where M6 is a nearly-Kaehler manifold and M7 is the G2-holonomy cone over M6.