Nonlinear perturbation theory extension of the Boltzmann code CLASS

2020/04/30 by Anton Chudaykin, Mikhail M. Ivanov, Oliver H. E. Philcox +1 · 2 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Algorithm #Astrophysics #Bayesian probability #Computational science #Computer science #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Markov chain Monte Carlo #Nonlinear system #Particle physics #Physics #Quantum mechanics #Redshift #Resummation #Spectral density #Statistical physics #astro-ph.CO

paper · pdf · doi:10.1103/physrevd.102.063533

published as Phys. Rev. D 102, 063533 (2020) · v1: 48 pages, 9 figures. v2: 56 pages, 14 figures, minor edits, version to appear in PRD. The code and custom-built BOSS likelihoods are available at https://github.com/Michalychforever/CLASS-PT and https://github.com/Michalychforever/lss_montepython

arxiv created 2020/08/29 · openalex publication_date 2020/09/28 · arxiv updated 2020/10/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We present a new open-source code that calculates one-loop power spectra and cross spectra for matter fields and biased tracers in real and redshift space. These spectra incorporate all ingredients required for a direct application to data: nonlinear bias and redshift-space distortions, infrared resummation, counterterms, and the Alcock-Paczynski effect. Our code is based on the Boltzmann solver class and inherits its advantageous properties: user friendliness, ease of modification, high speed, and simple interface with other software. We present detailed descriptions of the theoretical model, the code structure, approximations, and accuracy tests. A typical end-to-end run for one cosmology takes 0.3 seconds, which is sufficient for Markov chain Monte Carlo parameter extraction. As an example, we apply the code to the Baryon Oscillation Spectroscopic Survey (BOSS) data and infer cosmological parameters from the shape of the galaxy power spectrum.

Citations

• Cosmological perturbation theory in 1+1 dimensions
• Weak Gravitational Lensing of the CMB
• Nonlinear Evolution of the Bispectrum of Cosmological Perturbations
• The Shape of the Sloan Digital Sky Survey Data Release 5 Galaxy Power Spectrum
• Efficient sampling of fast and slow cosmological parameters
• Redshift Space Distortions in the Effective Field Theory of Large Scale Structures
• Massive neutrinos and cosmology
• Resumming cosmological perturbations via the Lagrangian picture: One-loop results in real space and in redshift space
• Flowing with time: a new approach to non-linear cosmological perturbations
• The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications
• EFT of large scale structures in redshift space
• The Effective Field Theory of Large-Scale Structure in the presence of Massive Neutrinos
• Cosmological Parameters from the BOSS Galaxy Power Spectrum
• GetDist: a Python package for analysing Monte Carlo samples
• Cosmological parameters and neutrino masses from the final Planck and full-shape BOSS data

Cited by

• Multi-tracer beyond linear theory
• Smooth sailing or ragged climb? -- Increasing the robustness of power spectrum de-wiggling and ShapeFit parameter compression