Cosmological Constraints on Neutrino Masses in a Second-Order CPL Dark Energy Model

Abstract

Recent DESI results indicate a strong preference for dynamical dark energy (DE) when baryon acoustic oscillation (BAO) measurements are combined with supernovae (SNe) and cosmic microwave background (CMB) data using the Chevallier-Polarski-Linder (CPL) parameterization. We analyze the exponential (EXP) parameterization, which introduces a second-order correction to CPL. We determine and compare the 95% upper bounds on the sum of neutrino masses for three dark energy (DE) models -- $\Lambda$CDM, CPL, and EXP -- across four neutrino mass hierarchies (1 massive/2 massless, degenerate, normal, inverted) and multiple dataset combinations (CMB$+$BAO, CMB$+$BAO$+$PantheonPlus, CMB$+$BAO$+$DESY5), employing both Bayesian and frequentist frameworks with physical lower limits from oscillation experiments (0.059 eV and 0.11 eV). Our results show that CPL yields tighter ($\lesssim 10$%) bounds compared to EXP. We further confirm earlier findings that neutrino mass constraints are only mildly sensitive to the assumed hierarchy and that the frequentist bounds are tighter than Bayesian ones. Furthermore, the imposed oscillation lower limits, the datasets used and the DE parameterizations play a crucial role in the inferred cosmological neutrino mass bounds. For the datasets, hierarchies, and DE parameterizations considered, we find no statistically significant evidence for nonzero neutrino mass consistent with oscillation lower limits.

21 pages, 11 figures. Published in Physics of the Dark Universe (Matches published version)

References in corpus (46)

• The Pantheon+ Analysis: Cosmological Constraints
• The fate of hints: updated global analysis of three-flavor neutrino oscillations
• DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations
• Massive neutrinos and cosmology
• The Pantheon+ Analysis: The Full Dataset and Light-Curve Release
• 2020 Global reassessment of the neutrino oscillation picture
• Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity
• DESI DR2 Results II: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints
• The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
• Towards a precision calculation of $N_{\mathrm{eff}}$ in the Standard Model II: Neutrino decoupling in the presence of flavour oscillations and finite-temperature QED
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Neutrino decoupling including flavour oscillations and primordial nucleosynthesis
• A precision calculation of relic neutrino decoupling
• The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
• GetDist: a Python package for analysing Monte Carlo samples
• A parametric model for dark energy
• CMB power spectra and cosmological parameters from Planck PR4 with CamSpec
• Cosmological parameters derived from the final (PR4) Planck data release
• Robust Preference for Dynamical Dark Energy in DESI BAO and SN Measurements
• New constraint on Early Dark Energy from Planck and BOSS data using the profile likelihood
• Constraints on Interacting Dark Energy Models from the DESI Baryon Acoustic Oscillation and DES Supernovae Data
• Updated Cosmological Constraints in Extended Parameter Space with Planck PR4, DESI Baryon Acoustic Oscillations, and Supernovae: Dynamical Dark Energy, Neutrino Masses, Lensing Anomaly, and the Hubble Tension
• Direct neutrino-mass measurement based on 259 days of KATRIN data
• Using non-DESI data to confirm and strengthen the DESI 2024 spatially-flat $w_0{w}_a$CDM cosmological parameterization result
• Interpreting DESI 2024 BAO: late-time dynamical dark energy or a local effect?
• Physical effects involved in the measurements of neutrino masses with future cosmological data
• Neutrino cosmology after DESI: tightest mass upper limits, preference for the normal ordering, and tension with terrestrial observations
• A fast test to assess the impact of marginalization in Monte Carlo analyses, and its application to cosmology
• Cosmology in Extended Parameter Space with DESI Data Release 2 Baryon Acoustic Oscillations: A 2$\sigma$+ Detection of Nonzero Neutrino Masses with an Update on Dynamical Dark Energy and Lensing Anomaly
• Robustness of dark energy phenomenology across different parameterizations
• Massive neutrinos and cosmic composition
• Model-agnostic assessment of dark energy after DESI DR1 BAO
• Model-independent cosmological inference post DESI DR1 BAO measurements
• Quintessence and phantoms in light of DESI 2025
• The DESI DR1/DR2 evidence for dynamical dark energy is biased by low-redshift supernovae
• Dynamical dark energy confronted with multiple CMB missions
• Testing signatures of phantom crossing through full-shape galaxy clustering analysis
• Quantifying the tension between cosmological and terrestrial constraints on neutrino masses
• Cosmological constraints on dark energy models using DESI BAO 2024
• Profile Likelihoods in Cosmology: When, Why and How illustrated with $\Lambda$CDM, Massive Neutrinos and Dark Energy
• Revisiting the impact of neutrino mass hierarchies on neutrino mass constraints in light of recent DESI data
• Accurately Weighing Neutrinos with Cosmological Surveys
• Non-parametric reconstruction of cosmological observables using Gaussian Processes Regression
• Constraints on Dark Energy Models Using Late Universe Probes
• Exploring parametrized dark energy models in interacting scenario
• 2D BAO vs 3D BAO: Hints for new physics?

Cited by in corpus (2)

• Joint Constraints on Neutrinos and Dynamical Dark Energy in Minimally Modified Gravity
• Measuring neutrino mass in light of ACT DR6 and DESI DR2