The Optimal Padé Polynomial for Reconstruction of Luminosity Distance Based on 10-fold Cross Validation

• Published in: The Astrophysical journal Vol. 988; no. 2; pp. 158 - 163
• Main Authors: Yu, Bo, Liu, Wen-Hu, Yang, Xiaofeng, Zhang, Tong-Jie, Tang, Yanke
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 01.08.2025; IOP Publishing
• Subjects: Akaike information criterion; Bayesian information criterion; Cross-validation; Observational cosmology
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/adeb81

The cosmography known as the Padé polynomials has been widely used in the reconstruction of luminosity distance, and the orders of Padé polynomials influence the reconstructed result derived from Padé approximation. In this paper, we present a more general scheme of selecting optimal Padé polynomial for reconstruction of luminosity distance based on 10-fold cross validation. Then the proposed scheme is applied to Pantheon+ data set. The numerical results clearly indicate that the proposed procedure has a remarkable ability to distinguish Padé approximations with different orders for the reconstruction of the luminosity distance. We conclude that the (2,1) Padé approximation is the optimal approach that can well explain Pantheon+ data at low and high redshifts. Future applications of this scheme could help choose the optimal model that is more suitable for cosmological observation data at hand and gain a deeper understanding of the Universe.