English

No preference for generalized emergent dark energy from current cosmological data

Cosmology and Nongalactic Astrophysics 2026-07-28 v1 General Relativity and Quantum Cosmology High Energy Physics - Theory

Abstract

In this work, we revisit the generalized emergent dark energy model by confronting it with DESI DR2 baryon acoustic oscillation measurements, in combination with joint CMB data from ACT, SPT, and Planck, as well as Type Ia supernova samples including Pantheon+^+, DES-Dovekie, and Union3. We find that the GEDE model remains compatible with the Λ\LambdaCDM paradigm, with no statistically significant preference for deviations when all datasets are combined. In particular, the key model parameter Δ\Delta is consistent with the Λ\LambdaCDM value Δ=0\Delta = 0 within 2σ2\sigma once SNe Ia data are included. Despite this overall agreement, the GEDE model does not exhibit the phantom crossing suggested by DESI DR2. Instead, the evolution of the dark energy equation of state w(z)w(z) indicates that the model behaves either as a full phantom (w<1w < -1) or quintessence (w>1w > -1), depending on the dataset combination, without a clear transition across w=1w = -1. When Pantheon+^+ data are included, the model converges closely to Λ\LambdaCDM with w1w \simeq -1. The GEDE model does not alleviate the existing cosmological tensions. The inferred values of H0H_0 remain in the range 67.967.9-69.8 km,s1,Mpc169.8\ \mathrm{km,s^{-1},Mpc^{-1}}, while the sound horizon rdr_d and clustering parameter S8S_8 remain consistent with Λ\LambdaCDM, failing to resolve the H0H_0 and S8S_8 tensions. Finally, both Gaussian significance levels (<2σ<2\sigma) and Bayesian evidence (lnBi,j<1\ln B_{i,j} < 1) indicate no statistically significant preference for GEDE over Λ\LambdaCDM. We conclude that, although DESI DR2 hints at dynamical dark energy, the GEDE model remains observationally indistinguishable from Λ\LambdaCDM and does not support the Quintom-B-type behavior suggested by DESI DR2.

Cite

@article{arxiv.2607.25539,
  title  = {No preference for generalized emergent dark energy from current cosmological data},
  author = {Vipin Kumar Sharma and Himanshu Chaudhary and Salvatore Capozziello and Dhruba Jyoti Gogoi and G. Mustafa},
  journal= {arXiv preprint arXiv:2607.25539},
  year   = {2026}
}

Comments

11 pages, 3 figures, Published in Physics of the Dark Universe, Volume 53 (2026), Article 102383