Dark energy, Ricci-nonflat spaces, and the Swampland
  It was recently pointed out that the existence of dark energy imposes highly
restrictive constraints on effective field theories that satisfy the Swampland
conjectures. We provide a critical confrontation of these constraints with the
cosmological framework emerging from the Salam-Sezgin model and its string
realization by Cvetic, Gibbons, and Pope. We also discuss the implication of
the constraints for string model building.
