Resummed Kinetic Field Theory: a model of coupled baryonic and dark matter

Abstract

We present a new analytical description of cosmic structure formation in a mixture of dark and baryonic matter, using the framework of Kinetic Field Theory (KFT) -- a statistical field theory for classical particle dynamics. So far, KFT has only been able to describe a single type of particles, sufficient to consider structure growth due to the gravitational interactions between dark matter. However, the influence of baryonic gas dynamics becomes increasingly relevant when describing smaller scales. In this paper, we thus demonstrate how to extend the KFT formalism as well as a previously presented resummation scheme towards describing such mixtures of two particle species. Thereby, the gas dynamics of baryons are accounted for using the recently developed model of Mesoscopic Particle Hydrodynamics. Assuming a flat $\Lambda$CDM Universe and a simplified model for the thermal gas evolution, we demonstrate the validity of this approach by computing the linear evolution of the individual and total matter power spectra between the epoch of recombination and today. Our results correctly reproduce the expected behaviour, showing a suppression of both baryonic and dark matter structure growth on scales smaller than the baryonic Jeans length, in good agreement with results from the numerical Boltzmann solver CLASS. Nonlinear corrections within this approach will be investigated in upcoming works.

23 pages, 9 figures, current version: added more explanatory material, content matches published version

References in corpus (7)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Resumming Cosmological Perturbations via the Lagrangian Picture: One-loop Results in Real Space and in Redshift Space
• Effects of Baryons and Dissipation on the Matter Power Spectrum
• The IR-resummed Effective Field Theory of Large Scale Structures
• Third-order Perturbation Theory With Non-linear Pressure
• Large-scale structure perturbation theory without losing stream crossing

Cited by in corpus (4)

• Cosmological perturbations for two cold fluids in $\Lambda$CDM
• Kinetic Field Theory for Cosmic Structure Formation
• Kinetic field theory: effects of modified gravity theories with screening mechanisms on non-linear cosmic density fluctuations
• Baryon-photon interactions in Resummed Kinetic Field Theory