Resummed Kinetic Field Theory: Using Mesoscopic Particle Hydrodynamics
  to Describe Baryonic Matter in a Cosmological Framework
  Recently, Bartelmann et al. presented a 'Kinetic Field Theory' (KFT)
formalism to tackle the difficulties of large scale structure formation. In
this approach, the dynamics of a non-equilibrium ensemble of classical
particles are examined based on methods of statistical field theory. So far,
only contributions coming from dark matter were considered, which is assumed to
pose an accurate description of our universe on very large scales.
Nevertheless, going to smaller scales, also baryonic contributions have to be
taken into account. Building on the ideas of Viermann et al. we present an
effective particle model of hydrodynamics to describe baryonic matter in a
cosmological framework. Using this model, the baryonic density contrast power
spectrum is computed to lowest perturbative order within the resummed KFT
framework of Lilow et al. We discuss the qualitative differences to the dark
matter case and perform a quantitative comparison to the baryonic spectrum
obtained from Eulerian perturbation theory. A subsequent paper will resolve the
problem of coupling both theories describing dark and baryonic matter,
respectively, to gain a full model of cosmic matter. Even though our focus is
on cosmological systems only, we want to emphasize that all methods presented
here are of a quite general fashion, making it applicable also to other fields.
