Flux Compactifications on $(S_2)^N$
  We investigate a simple extra-dimensional model and its four-dimensional vacua. This model has a two-form flux and a positive cosmological constant, and the extra dimensions are compactified as the product of $N$ two-spheres. The theory is an interesting laboratory because it is at once simple enough to be soluble but rich enough to exhibit many features not present in previous model landscapes. 
Adam R. Brown, Alex Dahlen, and Ali Masoumi
hep-th