Null tests with Gaussian Process

2025/03/20 by Gao, Shengqing, Gao, Qing, Gong, Yungui +1 · 5 citations
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences

paper · doi:10.48550/arxiv.2503.15943

Abstract

We investigate the null tests of spatial flatness and the flat ΛCDM model using the Baryon Acoustic Oscillation (BAO) data measured by the Dark Energy Spectroscopic Instrument (DESI), the cosmic chronometers (CCH) H(z) data, and the Union3 and Pantheon Plus type Ia supernovae (SNe Ia) datasets. We propose a novel non-parametric reconstruction of F_AP, D_M/r_d and D'_M/r_d from the DESI BAO data to perform the Ok diagnostic, and we also conduct the Ok diagnostic using the combination of CCH and SNe Ia data. The novel method avoids the issue of the dependence on cosmological parameters such as the value of the Hubble constant. There is no evidence of deviation from the flat ΛCDM model, nor is there any indication of dynamical dark energy found in the observational data. Since we employ a non-parametric reconstruction method, all the conclusions drawn in this paper remain robust and agnostic to any cosmological model and gravitational theory.

Cited by

• Is Dark Energy Dynamical in the DESI Era? A Critical Review
• Cosmological constraints on nonphantom dynamical dark energy with DESI Data Release 2 Baryon Acoustic Oscillations: A 3σ+ lensing anomaly
• Probing the Cosmic Distance Duality Relation via Non-Parametric Reconstruction for High Redshifts
• Reconstructing dark energy with model independent methods after DESI DR2 BAO
• Testing Cosmic Distance Duality Relation and Transparency with DESI DR2

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