A Supersymmetric and Smooth Compactification of M-theory to AdS(5)

We obtain smooth M-theory solutions whose geometry is a warped product of AdS_5 and a compact internal space that can be viewed as an S^4 bundle over S^2. The bundle can be trivial or twisted, depending on the even or odd values of the two diagonal monopole charges. The solution preserves N=2 supersymmetry and is dual to an N=1 D=4 superconformal field theory, providing a concrete framework to study the AdS_5/CFT_4 correspondence in M-theory. We construct analogous embeddings of AdS_4, AdS_3 and AdS_2 in massive type IIA, type IIB and M-theory, respectively. The internal spaces have generalized holonomy and can be viewed as S^n bundles over S^2 for n=4, 5 and 7. Surprisingly, the dimensions of spaces with generalized holonomy includes D=9. We also obtain a large class of solutions of AdS\times H^2.