  This talk is a status report on our study of quantum transport equations
relevant for baryogenesis computations. Our main finding is that, as a
consequence of localization in space, the quasiparticle picture of the plasma
dynamics breaks down at first non-trivial order in gradient expansion. While in
this talk we focus on bosons, we expect that a similar picture holds for
fermions. We then argue that the quasiparticle picture is recovered in the
adiabatic limit of frequent scattering.
