DESI DR1 Lyman-alpha data yields Δ²★=0.379±0.032 and n★=-2.309±0.019 at k★=0.009 km⁻¹s and z=3, sharpening N_eff, α_s, and β_s constraints by factors of 1.18-1.90 when combined with other probes.
hub Mixed citations
The Cosmic Linear Anisotropy Solving System ( CLASS) I: Overview
Mixed citation behavior. Most common role is method (65%).
abstract
The Cosmic Linear Anisotropy Solving System (CLASS) is a new accurate Boltzmann code, designed to offer a more user-friendly and flexible coding environment to cosmologists. CLASS is very structured, easy to modify, and offers a rigorous way to control the accuracy of output quantities. It is also incidentally a bit faster than other codes. In this overview, we present the general principles of CLASS and its basic structure. We insist on the friendliness and flexibility aspects, while accuracy, physical approximations and performances are discussed in a series of companion papers.
hub tools
citation-role summary
citation-polarity summary
representative citing papers
The velocity coherence scale R_v marks the onset of statistical homogeneity, is redshift-independent in comoving coordinates, and connects directly to the matter-radiation equality scale k_eq in standard cosmology.
Derives the power spectrum evolution and cross-spectra for arbitrary multi-species wave and particle dark matter, incorporating free-streaming, Jeans scales, and intrinsic fluctuations.
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.
CosmoGen employs evolutionary algorithms for symbolic regression to generate dark energy fluid models that alleviate S8 and H0 tensions, with Bayesian analysis of one model showing tension relief though weaker preference than LambdaCDM.
Cobaya is a modular Bayesian analysis code that exploits model interdependencies via automatic caching and a novel parameter-blocking algorithm to minimize sampling cost.
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.
An interacting sterile neutrino component via pseudoscalar mediator reconciles CMB and DESI DR2 BAO measurements with 2.7 sigma preference and reduces H0 tension to 2.4 sigma.
Bursty high-redshift star formation boosts LIM shot-noise by line-dependent factors B_λ of 2.5-7 at z~6 via convolution of SFR correlations with SPS kernels, improving auto-spectrum detectability while degrading clustering measurements.
The GW-galaxy cross-correlation method, unified with spectral sirens in a harmonic framework, can measure H0 to 1% and Omega_m to 5% precision with 2 years of data from next-generation detectors like Einstein Telescope and Cosmic Explorer.
COLA-based hybrid emulator reproduces nonlinear power spectrum boosts in w0wa models to <2% error vs EuclidEmulator2 and produces <0.3σ shifts in LSST-like cosmic shear parameter constraints.
ACT DR6 yields a 2.3% precise CMB lensing power spectrum with A_lens = 1.013 ± 0.023 relative to Planck 2018 Lambda CDM, giving S8 = 0.818 ± 0.022 and no evidence for suppressed structure growth.
Estimators from squeezed bispectrum and collapsed trispectrum recover unbiased small-scale matter power spectrum covariance at the percent level using 25 Quijote simulations.
Two-field axion-like early dark energy reduces Hubble tension to 1.5 sigma residual and improves high-ell CMB fits over single-field models.
LTIT is a constrained interacting dark energy framework with late-activating variable coupling to CDM that keeps pre-recombination effects below 0.4 percent while permitting sub-percent to several-percent late-time shifts in growth.
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.
Validates redshift-space power spectrum and bispectrum analysis on Abacus-PNG mocks to recover unbiased f_NL constraints for Euclid spectroscopic sample.
Model-independent reconstruction finds 96.7-98.5% probability of phantom crossing if recombination is standard, but early new physics to ease Hubble tension weakens this preference while requiring unrealistically high matter density.
Numerical multi-field analysis of Higgs-R² inflation with kinetic mixing identifies two regimes: moderate ξ_h produces localized features in the curvature power spectrum via isocurvature transfer, while weak ξ_h leaves a nearly featureless spectrum with residual isocurvature.
Reanalysis of DESI full-shape clustering data tightens constraints on neutrino mass, spatial curvature, and dark energy equation-of-state parameters relative to BAO-only results.
Reassessment of the CatWISE2020 quasar dipole with comprehensive simulations lowers the anomaly significance from 4.9σ to 3.27–3.63σ but leaves it unexplained by clustering or mask effects alone.
CMB-only data give f_EDE < 0.07 at 95% CL with no strong AEDE signal, while CMB+DESI yields f_EDE = 0.055^{+0.024}_{-0.047} at 68% CL and lowers Hubble tension to 2.6 sigma.
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.
citing papers explorer
-
Cosmological analysis of the DESI DR1 Lyman alpha 1D power spectrum
DESI DR1 Lyman-alpha data yields Δ²★=0.379±0.032 and n★=-2.309±0.019 at k★=0.009 km⁻¹s and z=3, sharpening N_eff, α_s, and β_s constraints by factors of 1.18-1.90 when combined with other probes.
-
The velocity coherence scale: a novel probe of cosmic homogeneity and a potential standard ruler
The velocity coherence scale R_v marks the onset of statistical homogeneity, is redshift-independent in comoving coordinates, and connects directly to the matter-radiation equality scale k_eq in standard cosmology.
-
Growth of Structure in Multi-species Wave Dark Matter
Derives the power spectrum evolution and cross-spectra for arbitrary multi-species wave and particle dark matter, incorporating free-streaming, Jeans scales, and intrinsic 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.
-
CosmoGen: A genetic algorithm framework for the exploration of dark energy dynamics
CosmoGen employs evolutionary algorithms for symbolic regression to generate dark energy fluid models that alleviate S8 and H0 tensions, with Bayesian analysis of one model showing tension relief though weaker preference than LambdaCDM.
-
Cobaya: Code for Bayesian Analysis of hierarchical physical models
Cobaya is a modular Bayesian analysis code that exploits model interdependencies via automatic caching and a novel parameter-blocking algorithm to minimize sampling cost.
-
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.
-
Recoupled Dark Radiation reconciling CMB and DESI BAO measurements
An interacting sterile neutrino component via pseudoscalar mediator reconciles CMB and DESI DR2 BAO measurements with 2.7 sigma preference and reduces H0 tension to 2.4 sigma.
-
When galaxies burst: enhanced shot-noise for line-intensity mapping in the JWST era
Bursty high-redshift star formation boosts LIM shot-noise by line-dependent factors B_λ of 2.5-7 at z~6 via convolution of SFR correlations with SPS kernels, improving auto-spectrum detectability while degrading clustering measurements.
-
A unified harmonic framework for dark siren cosmology
The GW-galaxy cross-correlation method, unified with spectral sirens in a harmonic framework, can measure H0 to 1% and Omega_m to 5% precision with 2 years of data from next-generation detectors like Einstein Telescope and Cosmic Explorer.
-
Modeling nonlinear scales for dynamical dark energy cosmologies with COLA
COLA-based hybrid emulator reproduces nonlinear power spectrum boosts in w0wa models to <2% error vs EuclidEmulator2 and produces <0.3σ shifts in LSST-like cosmic shear parameter constraints.
-
The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
ACT DR6 yields a 2.3% precise CMB lensing power spectrum with A_lens = 1.013 ± 0.023 relative to Planck 2018 Lambda CDM, giving S8 = 0.818 ± 0.022 and no evidence for suppressed structure growth.
-
If at First You Don't Succeed, Trispectrum: I. Estimating the Matter Power Spectrum Covariance with Higher-Order Statistics
Estimators from squeezed bispectrum and collapsed trispectrum recover unbiased small-scale matter power spectrum covariance at the percent level using 25 Quijote simulations.
-
Double the axions, half the tension: multi-field early dark energy eases the Hubble tension
Two-field axion-like early dark energy reduces Hubble tension to 1.5 sigma residual and improves high-ell CMB fits over single-field models.
-
Late-Transition Interacting Thawer Dark Energy: Physics and Validation
LTIT is a constrained interacting dark energy framework with late-activating variable coupling to CDM that keeps pre-recombination effects below 0.4 percent while permitting sub-percent to several-percent late-time shifts in growth.
-
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.
-
Euclid preparation: Testing multi-field inflation with galaxy power spectrum and bispectrum
Validates redshift-space power spectrum and bispectrum analysis on Abacus-PNG mocks to recover unbiased f_NL constraints for Euclid spectroscopic sample.
-
Exploring the interplay of late-time dynamical dark energy and new physics before recombination
Model-independent reconstruction finds 96.7-98.5% probability of phantom crossing if recombination is standard, but early new physics to ease Hubble tension weakens this preference while requiring unrealistically high matter density.
-
Isocurvature-induced features in multi-field Higgs-$R^2$ inflation
Numerical multi-field analysis of Higgs-R² inflation with kinetic mixing identifies two regimes: moderate ξ_h produces localized features in the curvature power spectrum via isocurvature transfer, while weak ξ_h leaves a nearly featureless spectrum with residual isocurvature.
-
Reanalyzing DESI DR1: 2. Constraints on Dark Energy, Spatial Curvature, and Neutrino Masses
Reanalysis of DESI full-shape clustering data tightens constraints on neutrino mass, spatial curvature, and dark energy equation-of-state parameters relative to BAO-only results.
-
The CatWISE2020 Quasar dipole: A Reassessment of the Cosmic Dipole Anomaly
Reassessment of the CatWISE2020 quasar dipole with comprehensive simulations lowers the anomaly significance from 4.9σ to 3.27–3.63σ but leaves it unexplained by clustering or mask effects alone.
-
SPT-3G D1: Axion Early Dark Energy with CMB experiments and DESI
CMB-only data give f_EDE < 0.07 at 95% CL with no strong AEDE signal, while CMB+DESI yields f_EDE = 0.055^{+0.024}_{-0.047} at 68% CL and lowers Hubble tension to 2.6 sigma.
-
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.
-
The End of the First Act: Spectral Running, Interacting Dark Radiation, and the Hubble Tension in Light of ACT DR6 Data
Including spectral running α_s, β_s and self-interacting dark radiation relaxes the ACT DR6 bound on ΔN_eff to <0.58 and lowers the Hubble tension to 2.2σ with three extra parameters.
-
Reconstructing inflationary features on large scales using genetic algorithm
Genetic algorithm reconstructs single-field inflationary models with features in the scalar power spectrum that fit Planck 2018 CMB data better by Δχ² ≲ -10 and suggest alternative background parameters.
-
Beyond the Standard Model of Cosmology: Testing new paradigms with a Multiprobe Exploration of the Dark Universe
Proposes primordial black holes from modified small-scale fluctuations and entropic acceleration in expanding spacetime as explanations for dark matter and dark energy.
-
A generic $\omega_b$ tension in early-time solutions to the Hubble tension
Early-time Hubble tension solutions generically raise the preferred baryon density ω_b, conflicting with BBN deuterium constraints and producing poorer fits to CMB, BAO, supernova, and BBN data than ΛCDM.
-
Probing late-time deviations from $\Lambda$CDM with a quadratic dark energy expansion
The QDEE model fits combined cosmological datasets better than Lambda CDM, shifts the Hubble constant higher, and shows strong Bayesian evidence in its favor.
-
Comparison of Halo Model and Simulation Predictions for Projected-Field Kinematic Sunyaev-Zel'dovich Cross-Correlations
Halo model predictions match Websky simulations well for Planck filters but differ by ~20% for Simons Observatory filters, exceeding error bars and consistent with missing higher-order terms in the kSZ signal.
-
Revisiting $\Lambda$CDM extensions in light of re-analyzed CMB data
Re-analysis with PR4 Planck likelihoods reduces lensing anomaly significance and curvature preference in Lambda CDM extensions while indicating a preference for evolving dark energy consistent with DESI.
-
Extended Dark Energy analysis using DESI DR2 BAO measurements
Extended analysis of DESI DR2 data confirms robust evidence for dynamical dark energy with phantom crossing preference, stable under parametric and non-parametric modeling.
-
Reionization History and Neutrino Mass
Reionization histories with higher total optical depth can move the best-fit neutrino mass sum to positive values around 0.06 eV within 95% confidence from CMB and BAO data.
-
The Status of Gravitational Vector Perturbations with Recent CMB Data
Recent CMB datasets tighten 95% CL upper bounds on vector-mode amplitude r_v to 1.3e-4 (neutrino isocurvature), 6.8 (octupole), and 4.2 (sourced) at k=0.05 Mpc^-1, with no significant detection.
-
In-depth analysis of the clustering of dark matter particles around primordial black holes. Part III: CMB constraints
CMB data limits the s-wave annihilation cross section of thermal dark matter particles to ≲ 10^{-30} cm³/s scaled by PBH fraction and mass for PBHs heavier than ~10^{-10} solar masses.
-
Constraints on Coupled Dark Energy in the DESI Era
New cosmological data mildly favor a small coupling between dark matter and a scalar dark energy field at |β| ≈ 0.03 while allowing an effective phantom-crossing equation of state.
-
Primordial magnetic fields in the light of upcoming post-EoR Lyman-$\alpha$ and 21-cm observations
Forecasts show DESI-like and SKA1-Mid observations could constrain primordial magnetic field amplitude and spectral index to roughly 10% precision via 21cm auto-spectrum and Lyα-21cm cross-spectrum.
-
Mapping the redshift drift at various redshifts through cosmography
Cosmographic Taylor and Padé models fitted to Pantheon+SH0ES+GRB+DESI BAO data yield redshift drift predictions compatible with ΛCDM and ω0ω1CDM at 1-2σ, with mock drift data tightening q0 and j0 bounds.
-
Planck 2018 results. X. Constraints on inflation
Updated Planck CMB measurements give ns = 0.9649 ± 0.0042, r < 0.056, confirm flatness at 0.4 percent, and show no evidence for scale-dependent features or non-slow-roll dynamics in the inflaton potential.
-
Study of the cosmological tensions and DESI-DR2 in the framework of the Little Rip model
The Little Rip model reduces the Hubble tension below 3σ with CMB plus BAO data but only improves the statistical fit to CMB data alone per Bayes factors, and shifts toward quintessence behavior when DESI-DR2 is included.
-
2020 Global reassessment of the neutrino oscillation picture
Updated global fit of neutrino oscillation data gives precise measurements of mixing parameters with a 2.5 sigma preference for normal mass ordering.
-
The Hubble Tension and Early Dark Energy
The Hubble tension between local and early-universe expansion-rate measurements may be resolved by early dark energy that speeds up expansion before recombination while satisfying existing constraints.