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.
hub Mixed citations
The Cosmic Linear Anisotropy Solving System (CLASS) IV: Efficient implementation of non-cold relics
Mixed citation behavior. Most common role is method (60%).
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.
hub tools
citation-role summary
citation-polarity summary
representative citing papers
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 uGMRT, MeerKAT and SKA1-MID.
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 in speed and precision.
Massive neutrinos and dark matter-baryon interactions produce degenerate suppressions in the CMB lensing power spectrum at next-generation experiment precision.
Future global 21-cm observations could beat CMB limits on TeV-scale decaying dark matter for lifetimes ≳10^15 s, especially for decays into neutrinos.
Including neutrino density isocurvature in fits to ACT DR6, DESI DR2, and DES data yields ∑m_ν < 0.057 eV at 95% CL in ΛCDM with no detection of the isocurvature mode.
New constraints on dark radiation parameters from recent cosmological datasets show the model alleviates the Hubble tension with SH0ES inclusion while remaining consistent with standard expectations without it.
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 + supernova fits with z_† > 2.4.
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.
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 observable by HERA and SKA.
A 1D convolutional neural network reconstructs the dark-matter phase-space distribution from the matter power spectrum with greater accuracy and broader applicability than an earlier empirical formula.
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.
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.
A review of string-inspired dynamical dark energy models claiming compatibility with DESI's hints of evolving dark energy under swampland constraints.
citing papers explorer
-
Multi-species Dark Matter with Warmth and Randomness
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.
-
Effects of primordial magnetic fields on 21 cm multifrequency angular power spectra
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 uGMRT, MeerKAT and SKA1-MID.
-
The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
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 in speed and precision.
-
Massive neutrinos and interacting dark matter look alike through the lens of lensing
Massive neutrinos and dark matter-baryon interactions produce degenerate suppressions in the CMB lensing power spectrum at next-generation experiment precision.
-
Cosmological constraints on TeV-scale dark matter subcomponents decaying between recombination and reionisation
Future global 21-cm observations could beat CMB limits on TeV-scale decaying dark matter for lifetimes ≳10^15 s, especially for decays into neutrinos.
-
Constraints on the Sum of Neutrino Masses from ACT DR6 and DESI DR2 Considering Isocurvature Initial Conditions
Including neutrino density isocurvature in fits to ACT DR6, DESI DR2, and DES data yields ∑m_ν < 0.057 eV at 95% CL in ΛCDM with no detection of the isocurvature mode.
-
Exploring the Dark Sector: Interacting Radiation in Light of Modern Cosmological Probes
New constraints on dark radiation parameters from recent cosmological datasets show the model alleviates the Hubble tension with SH0ES inclusion while remaining consistent with standard expectations without it.
-
Negative neutrino mass or negative dark energy?
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 + supernova fits with z_† > 2.4.
-
Constraints on Neutrino Physics from DESI DR2 BAO and DR1 Full Shape
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.
-
Primordial Magnetic Fields at Cosmic Dawn: 21-cm Forecasts with HERA and SKA
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 observable by HERA and SKA.
-
Machine Learning Does It and Does It Better: Unearthing Primordial Dark-Matter Velocities from the Matter Power Spectrum
A 1D convolutional neural network reconstructs the dark-matter phase-space distribution from the matter power spectrum with greater accuracy and broader applicability than an earlier empirical formula.
-
Taking Inventory of the Most Promising Lensed Radio Sources for Constraining Fundamental Properties of Dark Matter
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.
-
Seasons of Dark Matter Freeze-In Shaped by the Weather of the Early Universe
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.
-
Breaking Free from the Swampland of Impossible Universes through the DESI Portal
A review of string-inspired dynamical dark energy models claiming compatibility with DESI's hints of evolving dark energy under swampland constraints.