English

Interacting dark energy after DESI DR2: a challenge for $\Lambda$CDM paradigm?

Cosmology and Nongalactic Astrophysics 2026-01-28 v3 General Relativity and Quantum Cosmology

Abstract

We investigate the scenario of interacting dark energy through a detailed confrontation with various observational datasets. We quantify the interaction in a general way, through the deviation from the standard scaling of the dark matter energy density. We use the cosmic microwave background (CMB) data from Planck 2018, data from Baryon Acoustic Oscillations (BAO) from the recently released DESI DR2, observational Hubble Data from Cosmic Chronometers (CC), and finally various Supernova Type Ia (SNIa) datasets (PantheonPlus, Union3 and DESY5). For the basic and simplest interacting model we find a mild preference of the interaction at slightly more than 1σ1\sigma however still within 2σ2\sigma, and thus no strong evidence of interaction is found. However, comparison with Λ\Lambda cold dark matter (Λ\LambdaCDM) scenario through Δχmin2\Delta \chi^2_{\rm min}, Akaike Information Criterion and Bayesian analysis, reveals a mixed picture, namely according to Δχmin2\Delta \chi^2_{\rm min} the interaction is mildly favored by most of the datasets, while the remaining statistical measures are inclined toward Λ\LambdaCDM.

Keywords

Cite

@article{arxiv.2504.00994,
  title  = {Interacting dark energy after DESI DR2: a challenge for $\Lambda$CDM paradigm?},
  author = {Supriya Pan and Sivasish Paul and Emmanuel N. Saridakis and Weiqiang Yang},
  journal= {arXiv preprint arXiv:2504.00994},
  year   = {2026}
}

Comments

12 pages including references; 4 tables, 6 captioned figures; published version in Phys. Rev. D

R2 v1 2026-06-28T22:42:44.282Z