A first comparison of Kinetic Field Theory with Eulerian Standard Perturbation Theory. Issue 6 (17th June 2021)

• Record Type: Journal Article
• Authors: Kozlikin, Elena; Lilow, Robert; Fabis, Felix; Bartelmann, Matthias
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2021:Issue 6(2021)
• Publication Date: 2021-06-17
• Subjects: cosmological perturbation theory -- power spectrum; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2021/06/035
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: We present a detailed comparison of the newly developed particle-based Kinetic Field Theory framework for cosmic large-scale structure formation with the established formalism of Eulerian Standard Perturbation Theory. We highlight the qualitative differences of both approaches by a comparative analysis of the respective equations of motion and implementation of initial conditions. A natural starting point for a first quantitative comparison is given by the non-interacting regime of free-streaming kinematics. Our results suggest that Kinetic Field Theory contains a complete resummation of Standard Perturbation Theory in this regime. We further show that the exact free-streaming solution of Kinetic Field Theory cannot be recovered in any finite order of Standard Perturbation Theory. Kinetic Field Theory should therefore provide a better starting point for perturbative treatments of non-linear structure formation.