A first comparison of Kinetic Field Theory with Eulerian Standard Perturbation Theory
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.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- June 2021
- DOI:
- 10.1088/1475-7516/2021/06/035
- arXiv:
- arXiv:2012.05812
- Bibcode:
- 2021JCAP...06..035K
- Keywords:
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- cosmological perturbation theory;
- power spectrum;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Condensed Matter - Statistical Mechanics
- E-Print:
- JCAP06(2021)035