DESI DR2 Joint Analysis Shows AIC Favoring Two-Parameter Dynamical Dark Energy but BIC Penalizing Quadratic Extension
The arXiv analysis demonstrates that DESI DR2 data continue to favor dynamical dark energy under AIC but the extra parameter in quadratic w(z) is penalized by BIC. Two-parameter models (CPL, Wang) emerge as optimal while the parabolic extension is disfavored. Larger future datasets will be required to justify higher-order parameterizations.
Future surveys such as Euclid and Roman will enlarge the BAO and supernova samples by factors of several, tightening w(z) constraints. Only then can three-parameter or non-parametric reconstructions be tested without BIC rejection. Until then, two-parameter linear forms remain the minimal sufficient description for dynamical dark energy searches.
DESI collaboration: DR3 analysis will either push the CPL dynamical preference above 4.5σ or drop below 2.5σ within 24 months.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2609.02910)
- [2]Supporting Source(https://arxiv.org/abs/2404.03002)