Deriving Boltzmann Equations from Kadanoff-Baym Equations in Curved Space-Time

Understand

To calculate the baryon asymmetry in the baryogenesis via leptogenesis scenario one usually uses Boltzmann equations with transition amplitudes computed in vacuum.

• However, the hot and dense medium and, potentially, the expansion of the universe can affect the collision terms and hence the generated asymmetry.
• In this paper we derive the Boltzmann equation in the curved space-time from (first-principle) Kadanoff-Baym equations.
• As one expects from general considerations, the derived equations are covariant generalizations of the corresponding equations in Minkowski space-time.