Study of dynamical dark energy using DESI DR2 BAO, CMB, and Type Ia Supernovae data

@misc{wang2026study,
  title = {{Study of dynamical dark energy using DESI DR2 BAO, CMB, and Type Ia Supernovae data}},
  author = {Pin Wang and Ping Wang and Jielei Zhang},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.10567},
  eprint = {2609.10567},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.10567},
}

TY  - UNPB
TI  - Study of dynamical dark energy using DESI DR2 BAO, CMB, and Type Ia Supernovae data
AU  - Pin Wang
AU  - Ping Wang
AU  - Jielei Zhang
PY  - 2026
DA  - 2026/09/01
PB  - arXiv
DO  - 10.48550/arxiv.2609.10567
UR  - https://arxiv.org/abs/2609.10567
AB  - Dark Energy Spectroscopic Instrument (DESI) Collaboration reported an evidence for dynamical dark energy model using baryon acoustic oscillation (BAO) measurements from DESI Data Release 2 (DR2), cosmic microwave background (CMB), and three Type Ia Supernovae (SNe) data (Pantheon+, Union3, and DES-SN5YR) recently. The significances are from 2.8∼4.2σ depending on which SNe sample is used, and the highest significance is obtained based on the DES-SN5YR data. But more recently, Dark Energy Survey (DES) Collaboration recalibrated the DES-SN5YR data, and a significance of only 3.2σ is obtained based on the calibrated data, which is called DES-Dovekie. In this work, we perform a comprehensive analysis of five representative dynamical dark energy parametrization models, including Chevallier-Polarski-Linder (CPL), Barboza-Alcaniz (BA), exponential (EXP), logarithmic (LOG), and Jassal-Bagla-Padmanabhan (JBP), using DESI DR2 BAO, Planck CMB, ACT DR6, and SNe data from Pantheon+, Union3, and DES-Dovekie. Similarly, a significance of around 3σ is obtained based on the DES-Dovekie data. And the significances are 2.1∼3.7σ for different SNe samples and different parametrization models, indicating an evolutionary dark energy dynamics. Furthermore, a phantom-like behavior in the past and has transitioned into quintessence-like behavior today for the dynamical dark energy is preferred.
ER  -