Reconstruction of dark energy using DESI DR2

2025/11/04 by Zhang, Xue, Xu, Yin-Hao, Sang, Yu · 1 citation
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences

paper · doi:10.48550/arxiv.2511.02220

Abstract

Using a model-independent Gaussian process (GP) method to reconstruct the dimensionless luminosity distance D and its derivatives, we derive the evolution of the dimensionless Hubble parameter E, the deceleration parameter q, and the state parameter w of dark energy. We utilize the PantheonPlus, SH0ES, and Gamma Ray Burst (GRB) data to derive the dimensionless luminosity distance D. Additionally, we employ observational H(z) data (OHD) and baryon acoustic oscillations (BAO) from Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2) to obtain the first derivative of the dimensionless luminosity distance D^'. To obtain the reconstructed D and D^', we utilize the fiducial value from each dataset, with particular emphasis on the varying H₀. According to the reconstruction results obtained from PantheonPlus+SH0ES+GRB+OHD and PantheonPlus+SH0ES+GRB+OHD+DESI data, we find that E are consistent with the predictions of the ΛCDM model at a 2σ confidence level within the redshift range of z<2. However, the reconstruction results for q exhibit deviations from the ΛCDM model in the range of z<0.3. Furthermore, we observe that the mean value of w exhibits evolving behavior, transiting from w < -1 to w > -1 around z_{\rm wt}=0.464^+0.235_-0.120. Combining data from DESI DR2 can slightly enhance the accuracy of our constraints.

Citations

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Cited by

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