pith. sign in

arxiv: 1104.2935 · v3 · pith:UG4KSNBWnew · submitted 2011-04-14 · 🌌 astro-ph.CO

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

classification 🌌 astro-ph.CO
keywords darkmatteraccuracyclasscodesmassiveneutrinosnon-cold
0
0 comments X
read the original 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.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 10 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Multi-species Dark Matter with Warmth and Randomness

    astro-ph.CO 2025-10 unverdicted novelty 7.0

    Presents a general analytic framework based on truncated BBGKY hierarchy solved via Volterra equations for computing power spectra in multi-species dark matter with finite velocity dispersion and Poisson fluctuations.

  2. Effects of primordial magnetic fields on 21 cm multifrequency angular power spectra

    astro-ph.CO 2025-10 unverdicted novelty 7.0

    The paper calculates multifrequency angular power spectra of the 21 cm line for models with primordial magnetic fields of strength 4 nG and spectral indices -2.9 and -2.5, then estimates signal-to-noise ratios for uGM...

  3. The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes

    astro-ph.CO 2011-04 accept novelty 7.0

    CLASS implements a tunable baryon-photon tight-coupling approximation, a new ultra-relativistic fluid approximation, and a radiation streaming approximation that accounts for reionization, yielding simultaneous gains ...

  4. Massive neutrinos and interacting dark matter look alike through the lens of lensing

    astro-ph.CO 2025-11 unverdicted novelty 6.0

    Massive neutrinos and dark matter-baryon interactions produce degenerate suppressions in the CMB lensing power spectrum at next-generation experiment precision.

  5. Negative neutrino mass or negative dark energy?

    astro-ph.CO 2026-05 unverdicted novelty 5.0

    A sign-switching dark energy model (Λ_s CDM) recovers positive effective neutrino masses (0.055 ± 0.050 eV) consistent with oscillation data, unlike ΛCDM which prefers negative values (-0.075 eV), for DESI DR2 + CMB +...

  6. Primordial Magnetic Fields at Cosmic Dawn: 21-cm Forecasts with HERA and SKA

    astro-ph.CO 2026-05 unverdicted novelty 5.0

    Primordial magnetic fields enhance low-mass halo abundance at Cosmic Dawn, advancing Lyman-alpha coupling, X-ray heating and reionization and imprinting detectable signatures on global and fluctuating 21-cm signals ob...

  7. Cosmological constraints on TeV-scale dark matter subcomponents decaying between recombination and reionisation

    astro-ph.CO 2026-04 conditional novelty 5.0

    Future 21-cm observations may constrain TeV-scale decaying dark matter subcomponents more tightly than CMB data for lifetimes above 10^15 s, with strongest sensitivity for neutrino decay channels due to differences in...

  8. Constraints on Neutrino Physics from DESI DR2 BAO and DR1 Full Shape

    astro-ph.CO 2025-03 conditional novelty 5.0

    DESI DR2 BAO and full-shape data plus CMB yield ∑m_ν < 0.0642 eV (95% CL) under ΛCDM, in 3σ tension with oscillation lower limits, relaxed to <0.163 eV in w0waCDM.

  9. Taking Inventory of the Most Promising Lensed Radio Sources for Constraining Fundamental Properties of Dark Matter

    astro-ph.CO 2026-05 unverdicted novelty 4.0

    Reports results from two searches for new radio lenses in existing surveys and discusses the completeness of the population usable for constraining dark matter properties via astrometric perturbations.

  10. Seasons of Dark Matter Freeze-In Shaped by the Weather of the Early Universe

    hep-ph 2025-11 unverdicted novelty 4.0

    Variations in pre-nucleosynthesis cosmology produce distinct seasons in the phase-space distribution of freeze-in dark matter, directly affecting its warmness and mass bounds.