2018/03/31 by Andrei Lazanu, M. Liguori, Michele Liguori · 23 citations
Mathematics · Physics and Astronomy · #Bispectrum #Combinatorics #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Formalism (music) #Galaxies: Formation, Evolution, Phenomena #Loop (graph theory) #Mathematical physics #Mathematics #Nonlinear system #Order (exchange) #Particle physics #Perturbation (astronomy) #Perturbation theory (quantum mechanics) #Physics #Quantum electrodynamics #Quantum mechanics #Spectral density #Statistics #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2018/04/055
published in Journal of Cosmology and Astroparticle Physics 2018(04), 055 (Institute of Physics) · 20 pages, 3 figures, added another set of simulations in the comparison section, matches JCAP published version
openalex publication_date 2018/04/26 · arxiv created 2018/05/04 · arxiv updated 2018/05/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We evaluate for the first time the dark matter bispectrum of large-scale structure at two loops in the Standard Perturbation Theory and at three loops in the Renormalised Perturbation Theory (MPTBREEZE formalism), removing in each case the leading divergences in the integrals in order to make them infrared-safe. We show that the Standard Perturbation Theory at two loops can be employed to model the matter bispectrum further into the quasi-nonlinear regime compared to the one loop, up to k max ∼ 0.1 h /Mpc at z = 0, but without reaching a high level of accuracy. In the case of the MPTBREEZE method, we show that its bispectra decay at smaller and smaller scales with increasing loop order, but with smaller improvements decreases with loop order. At three loops, this model predicts the bispectrum accurately up to scales k max ∼ 0.17 h /Mpc at z = 0 and k max ∼ 0.24 h /Mpc at z = 1.