2012/11/07 by Francis Bernardeau, Atsushi Taruya, Takahiro Nishimichi · 39 citations
Mathematics · Physics and Astronomy · #Astronomy #COSMIC cancer database #Combinatorics #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Economics #Galaxies: Formation, Evolution, Phenomena #Loop (graph theory) #Mathematical physics #Mathematics #Order (exchange) #Physics #Propagator #astro-ph.CO
paper · pdf · doi:10.1103/physrevd.89.023502
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 89(2) (American Physical Society) · 22 pages, 11 figures
arxiv created 2012/11/07 · openalex publication_date 2014/01/08 · arxiv updated 2014/01/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We explore the properties of two-point cosmic propagators when perturbation theory loop corrections are consistently taken into account. We show in particular how the interpolation scheme proposed in [F. Bernardeau, M. Crocce, and R. Scoccimarro, Phys. Rev. D 85, 123519 (2012)] can be explicitly used up to two-loop order introducing the notion of regular parts for the contributing terms. Extending the one-loop results, we then derive and give semianalytical forms of the two-loop contributions for both the cosmic density and velocity propagators. These results are tested against numerical simulations and shown to significantly improve upon one-loop results for redshifts above 0.5. We found however that at lower redshift two-loop order corrections are too large partly due to a strong sensitivity of those terms to the small scale modes. We show that this dependence is expected to be even larger for higher order loop corrections both from theoretical investigations and numerical tests, the latter obtained with Monte Carlo evaluations of the three-loop contributions. This makes small-scale regularization schemes necessary for the use of such higher order corrections.