Bayesian and frequentist perspectives agree on dynamical dark energy
read the original abstract
Baryon acoustic oscillation data from the Dark Energy Spectroscopic Instrument (DESI) show evidence of a deviation from a cosmological constant $\Lambda$ within a Bayesian analysis. In this work, we validate that frequentist constraints from profile likelihoods on the Chevallier-Polarski-Linder parameters $w_0$, $w_a$ are in excellent agreement with the Bayesian constraints when combining with Planck cosmic microwave background, Planck and Atacama Cosmology Telescope lensing, and either Pantheon+ or Dark Energy Survey Y5 supernova data. Further, we assess which datasets drive these constraints by considering the contributions to the $\chi^2$ from the individual datasets. For profile likelihoods of the matter fraction $\Omega_\mathrm{m}$, such an investigation shows internal inconsistencies when assuming $\Lambda$, which are resolved when assuming a $w_0w_a$ dark-energy model. We infer the equations of state $w(z)$ at the pivot redshifts, supporting previous interpretations that current data appears to be more sensitive to the derivative of $w(z)$ rather than a mean offset from $\Lambda$. Thus our frequentist analysis corroborates previous findings on dynamical DE.
This paper has not been read by Pith yet.
Forward citations
Cited by 13 Pith papers
-
Dark energy perturbations and the robustness of cosmological neutrino-mass constraints
Dynamical dark energy with perturbations reverses the alleviation of neutrino mass tension seen in smooth models, preferring smaller masses due to degeneracies in growth data from CMB, BAO, RSD, and supernovae.
-
Nonlinear Matter Power Spectrum from relativistic $N$-body Simulations: $\Lambda_{\rm s}$CDM versus $\Lambda$CDM
Relativistic N-body simulations of Lambda_s CDM produce a redshift-dependent crest in the matter power spectrum ratio, peaking at 20-25% near the transition and leaving a 15-20% uplift at z=0 on group scales.
-
Reconstructing dark energy with fewer assumptions
Bin-wise uncorrelated reconstruction from DESI/SDSS BAO and Pantheon+/Union3.1/DES-Dovekie supernovae yields dark energy density peaking then declining and equation of state oscillating with phantom crossing near z~0....
-
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 +...
-
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...
-
The Bayesian view of DESI DR2 with unimpeded: Evidence and tension in a combined analysis with CMB and supernovae across cosmological models
Bayesian evidence computation on DESI DR2 plus Planck and supernovae eliminates the frequentist 3.1 sigma preference for w0waCDM over LambdaCDM when using the DES-Dovekie recalibration, yielding ln B = -0.30 favoring ...
-
Probing Dynamical Dark Energy with Late-Time Data: Evidence, Tensions, and the Limits of the $w_0w_a$CDM Framework
Evidence for dynamical dark energy in the w0waCDM framework is strongly dataset-dependent, driven by mismatches in low-redshift BAO distance ratios that produce divergent expansion histories and inconsistent Hubble te...
-
A Bayesian Perspective on Evidence for Evolving Dark Energy
Bayesian evidence favors a constant dark energy model for DESI plus Planck data and shows that apparent support for evolving dark energy with added supernova data stems from a 2.95 sigma tension between DESI and DES-S...
-
Intertwined Constraints in Extended Cosmologies: Dark Energy, Curvature, Neutrinos, and Inflation
Dynamical dark energy remains preferred across extended models while curvature, neutrino mass and inflation parameters show strong model dependence, with no resolution of the H0 tension.
-
Cosmological Viability of Exponential Infrared $f(T)$ Gravity
Exponential IR f(T) gravity Model I alleviates Hubble tension but is disfavoured by combined Planck/ACT/SPT+DESI+Pantheon+ data; Model II is ruled out because background constraints force unphysical shifts in CMB parameters.
-
Neutrino mass constraints in interacting dark energy models after DESI DR2
Upper bounds on total neutrino mass in four phenomenological interacting dark energy models are derived from DESI DR2 BAO plus CMB and SNIa data, showing strong dependence on the interaction term form and statistical ...
-
KiDS-Legacy: Constraining dark energy, neutrino mass, and curvature
KiDS-Legacy cosmic shear plus external probes yields S8 = 0.816 ± 0.006 in Lambda-CDM and consistent bounds on w0, wa, sum m_nu and Omega_K with no strong preference for extensions.
-
Effective Phantom Dark Energy: What Cosmological Reconstruction Does and Does Not Imply
Effective phantom dark energy is a background-level reconstruction that does not imply fundamental pathologies such as ghost instabilities or null energy condition violation by the underlying stress tensor.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.