title: Structure Formation in Dark and Baryonic Matter within Resummed Kinetic Field Theory
creator: Lilow, Robert
subject: ddc-500
subject: 500 Natural sciences and mathematics
subject: ddc-530
subject: 530 Physics
description: We combine a novel approach to cosmic structure formation called Kinetic Field Theory (KFT) with resummation methods to investigate the small-scale structure formation in dark and baryonic matter. For pure dark matter, we compute the first nonlinear corrections to the density contrast power spectrum and compare these to the results obtained in standard Eulerian perturbation theory (SPT). We find that we can precisely reproduce the SPT 1-loop result if we adopt the same expansion scheme as SPT. However, we also show that the natural expansion scheme of resummed KFT is actually fundamentally different and might thus be able to overcome the problems of SPT when trying to describe nonlinear structure formation. To describe the effect of baryons, we demonstrate how isothermal and adiabatic gas dynamics can be implemented consistently into resummed KFT and how a system of gravitationally coupled dark and baryonic matter can generally be treated in this framework. In the isothermal case, we further investigate the linear evolution of this coupled system in a cosmological setting. Our results show a suppression of the baryonic power spectrum on scales below approximately 1 Mpc/h which is qualitatively comparable to simulation results but underpredicts the effect by nearly an order of magnitude. Furthermore, simulations show an enhancement of the dark matter power spectrum absent in  our results. We expect these deviations to decrease once adiabatic gas dynamics and nonlinear corrections are taken into account.
date: 2018
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/24828/1/Dissertation_Robert_Lilow.pdf
identifier: DOI:10.11588/heidok.00024828
identifier: urn:nbn:de:bsz:16-heidok-248285
identifier:   Lilow, Robert  (2018) Structure Formation in Dark and Baryonic Matter within Resummed Kinetic Field Theory.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/24828/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng