Inflating vacua may be rare

Hertzberg, Tegmark, Kachru, Shelton, Ozcan wrote a review of stringy cosmology for cosmologists. They argue that moduli in the simplest string models can't be used to satisfy the slow-roll condition. The condition for inflation to be possible could thus be highly constraining. Tegmark thinks that type IIA vacua are the fittest ones.

See also Nude Socialist.