Moduli stabilization and cosmology of type IIB on SU(2)-structure orientifolds

We consider type IIB flux compactifications on six-dimensional SU(2)-structure manifolds with O5- and O7-planes. These six-dimensional spaces allow not only for F 3 and H 3 fluxes but also for F 1 and F 5 fluxes. We derive the four-dimensional N = 1 scalar potential for such compactifications and present one explicit example of a fully stabilized AdS vacuum with large volume and small string coupling. We then discuss cosmological aspects of these compactifications and derive several no-go theorems that forbid dS vacua and slow-roll inflation under certain conditions. We also study concrete examples of cosets and twisted tori and find that our no-go theorems forbid dS vacua and slow-roll inflation in all but one of them. For the latter we find a dS critical point with ϵ numerically zero. However, the point has two tachyons and eta-parameter η ≈ −3.1.