Skip to main content
Article thumbnail
Location of Repository

The Cosmic Linear Anisotropy Solving System (CLASS) IV: Efficient implementation of non-cold relics

By Julien Lesgourgues and Thomas Tram

Abstract

We present a new flexible, fast and accurate way to implement massive neutrinos, warm dark matter and any other non-cold dark matter relics in Boltzmann codes. For whatever analytical or numerical form of the phase-space distribution function, the optimal sampling in momentum space compatible with a given level of accuracy is automatically found by comparing quadrature methods. The perturbation integration is made even faster by switching to an approximate viscous fluid description inside the Hubble radius, which differs from previous approximations discussed in the literature. When adding one massive neutrino to the minimal cosmological model, CLASS becomes just 1.5 times slower, instead of about 5 times in other codes (for fixed accuracy requirements). We illustrate the flexibility of our approach by considering a few examples of standard or non-standard neutrinos, as well as warm dark matter models.Comment: 23 pages, 8 figures, 3 tables. Matches published version. Code available at http://class-code.ne

Topics: Astrophysics - Cosmology and Nongalactic Astrophysics
Year: 2015
DOI identifier: 10.1088/1475-7516/2011/09/032
OAI identifier: oai:arXiv.org:1104.2935
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://arxiv.org/abs/1104.2935 (external link)
  • http://class-code.net (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.