The DESI DR1/DR2 evidence for dynamical dark energy is biased by low-redshift supernovae

Abstract

Recently, a $3\sim 4\sigma$ preference for dynamical dark energy has been reported by the Dark Energy Spectroscopic Instrument (DESI) collaboration, which has inspired hot debates on new physics or systematics. In this paper, we reveal that this preference is significantly biased by an external low-redshift supernova (low-$z$ SN) sample, which was combined with the Dark Energy Survey SN program (DES-SN) in their Year-Five data release (DESY5). Using the intercept in the SN magnitude-distance relation as a diagnostic for systematics, we find not only large dispersions but also a large discrepancy in the low-$z$ SN sample when compared to the high-$z$ DES-SN sample within the single DESY5 compilation, in contrast to the uniform behavior found in the PantheonPlus data. Correcting for this low-$z$ systematics with or without including the cosmic microwave background data can largely reduce the preference for dynamical DE to be less than $2\sigma$. Therefore, the DESI preference for dynamical DE is biased by some unknown systematics in the low-$z$ SN sample.

v5, reorganized Table I and Table II, newly added panel for Figure 2, minor revision with better presentations, accepted for publication in Sci. China Phys. Mech. Astron

References in corpus (41)

• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• The Pantheon+ Analysis: Cosmological Constraints
• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations
• The Pantheon+ Analysis: The Full Dataset and Light-Curve Release
• Challenges for $\Lambda$CDM: An update
• Cosmological Evolution of a Quintom Model of Dark Energy
• The trouble with $H_0$
• Measurements of the Hubble Constant: Tensions in Perspective
• CfA3: 185 Type Ia Supernova Light Curves from the CfA
• The Expansion of the Universe is Faster than Expected
• The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
• DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars
• DESI 2024 IV: Baryon Acoustic Oscillations from the Lyman Alpha Forest
• The Carnegie Supernova Project I: Third Photometry Data Release of Low-Redshift Type Ia Supernovae and Other White Dwarf Explosions
• DESI 2024 VII: Cosmological Constraints from the Full-Shape Modeling of Clustering Measurements
• The Pantheon+ Analysis: SuperCal-Fragilistic Cross Calibration, Retrained SALT2 Light Curve Model, and Calibration Systematic Uncertainty
• DESI 2024: Reconstructing Dark Energy using Crossing Statistics with DESI DR1 BAO data
• Interacting Dark Energy after DESI Baryon Acoustic Oscillation measurements
• Assessing observational constraints on dark energy
• Interpreting DESI's evidence for evolving dark energy
• Scant evidence for thawing quintessence
• Quintessential interpretation of the evolving dark energy in light of DESI
• 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
• The Pantheon+ Analysis: Improving the Redshifts and Peculiar Velocities of Type Ia Supernovae Used in Cosmological Analyses
• The Pantheon+ Analysis: Evaluating Peculiar Velocity Corrections in Cosmological Analyses with Nearby Type Ia Supernovae
• 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?
• Hints of Nonminimally Coupled Gravity in DESI 2024 Baryon Acoustic Oscillation Measurements
• Matching current observational constraints with nonminimally coupled dark energy
• Evidence for suppression of structure growth in the concordance cosmological model
• Quintom cosmology and modified gravity after DESI 2024
• A new diagnostic for the null test of dynamical dark energy in light of DESI 2024 and other BAO data
• Quantifying Scalar Field Dynamics with DESI 2024 Y1 BAO measurements
• Model-independent cosmological inference post DESI DR1 BAO measurements
• $f(T)$ gravity after DESI Baryon Acoustic Oscillation and DES Supernovae 2024 data
• DESI Dark Energy Time Evolution is Recovered by Cosmologically Coupled Black Holes
• No-go guide for the Hubble tension: late-time or local-scale new physics
• Key drivers of the preference for dynamic dark energy
• Narrowing down the Hubble tension to the first two rungs of distance ladders
• Dynamical dark energy in light of cosmic distance measurements II: a study using current observations

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• Cosmological implications of tracker scalar fields: Testing the evidence for dynamical dark energy with recent data
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• Null energy condition violation and beyond Horndeski physics in light of DESI DR2 data
• Testing the cosmic distance duality relation with baryon acoustic oscillations and supernovae data
• Revisiting model-independent constraints on spatial curvature and cosmic ladders calibration: updated and forecast analyses
• Dark Energy in the DESI Era: A Brief Review of Evidence, Beyond-$\Lambda$CDM Interpretations, and Tensions
• Lensing amplitude anomaly and varying electron mass alleviate the Hubble and $S_8$ tensions
• Evidence for evolving dark energy from DESI DR2 BAO and Pantheon${}^{+}$, DES-Dovekie, and Union3
• Measuring neutrino mass in light of ACT DR6 and DESI DR2
• Updated observational constraints on $\varphi$CDM dynamical dark energy cosmological models
• Is Dark Energy Changing? Probing the Universe's Expansion with present and future astronomical probes
• A short review on Quintom dark energy theory
• Assessing the Robustness of the CPL Parametrization to Basis and Prior Variations: Insights from DESI DR2 BAO Data
• Cosmological Constraints on Neutrino Masses in a Second-Order CPL Dark Energy Model
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• Is the $\Lambda$CDM Model in Crisis?
• Controlled Tension Forecasting: Quantifying Cross-Probe Biases in ${\omega }_0{\omega }_a$CDM
• Revisiting the equation of state of dark energy from DESI BAO with SNe Ia and CMB
• A new magnitude--redshift relation based on Type Ia supernovae
• Sector-Resolved Bayesian Model Averaging for DESI-Era Cosmology