What question did this study set out to answer?

The research investigates the dependence of dynamical dark energy results on analysis methods used in DESI datasets.

December 9, 2025Open Access

On the Analysis Dependence of DESI Dynamical Dark Energy

ECEoin Ó ColgáinAtlantic University MSM. M. Sheikh-JabbariThe Abdus Salam International Centre for Theoretical Physics (ICTP)

Key Points

The research investigates the dependence of dynamical dark energy results on analysis methods used in DESI datasets.
Defined a likelihood for w0waCDM model and fitted it to DESI constraints.
Incorporated CMB constraints alongside Full-Shape and BAO modeling.
Compared results from DR1 and DR2 datasets to examine dynamical DE signals.
Confirmed no dynamical DE signal in Full-Shape modeling, despite expectations from BAO and CMB.
Found evidence of late-time accelerated expansion (q0<0) at ≳3.4σ in FS modeling + BAO.
Showed discrepancies in q0 findings between DR1/DR2 BAO and FS analysis.

Abstract

We continue scientific scrutiny of the DESI dynamical dark energy (DE) claim by explicitly demonstrating that the result depends on the analysis pipeline. Concretely, we define a likelihood that converts the w0waCDM model back into the (flat) ΛCDM model, which we fit to DESI constraints on the ΛCDM model from DR1 Full-Shape (FS) modeling and BAO. We further incorporate CMB constraints. Throughout, we find that w0 and wa are within 1σ of the ΛCDM model. Our work makes it explicit that, in contrast to DR1 and DR2 BAO, there is no dynamical DE signal in FS modeling, even when combined with BAO and CMB. Moreover, one confirms late-time accelerated expansion today (q0<0) at ≳3.4σ in FS modeling + BAO. On the contrary, DR1 and DR2 BAO fail to confirm q0<0 under similar assumptions. Our analysis highlights the fact that trustable scientific results should be independent of the analysis pipeline.

KI fragen

Bookmark

View Full Paper