Neutrino Masses, Baryon Asymmetry, Dark Matter and the Moduli Problem : A Complete Framework

Understand

Recent developments in string theory have led to "realistic" string compactifications which lead to moduli stabilization while generating a hierarchy between the Electroweak and Planck scales at the same time.

• However, this seems to suggest a rethink of our standard notions of cosmological evolution after the end of inflation and before the beginning of BBN.
• We argue that within classes of realistic string compactifications, there generically exists a light modulus with a mass comparable to that of the gravitino which generates a large late-time entropy when it decays.
• Therefore, all known mechanisms of generating the baryon asymmetry of the Universe in the literature have to take this fact into account.