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Ahmad Mehrabi

Ahmad Mehrabi

Academic rank: Associate Professor
ORCID:
Education: PhD.
ScopusId: 36705117200
HIndex:
Faculty: Faculty of Science
Address:
Phone:

Research

Title
Nonparametric modeling of cosmological database on the χ 2 distribution
Type
JournalPaper
Keywords
dark energy - chi-squared
Year
2021
Journal PHYSICAL REVIEW D
DOI
Researchers ، Ahmad Mehrabi

Abstract

In the ΛCDM model, cosmological observations from the late and recent Universe reveal a puzzling ∼4.5σ tension in the current rate of Universe expansion. In addition to the various scenarios suggested to resolve the tension, a nonparametric modeling may provide useful insights. In this paper, we look at three well-known nonparametric methods: the smoothing method, the genetic algorithm, and the Gaussian process. Considering these three methods, we employ the recent Hubble parameter data to reconstruct the rate of Universe expansion and supernovae Pantheon sample to reconstruct the luminosity distance. In contrast to similar studies in the literature, the chi-squared distribution has been used to construct a reliable criterion to select a reconstruction. Finally, we compute the current rate of Universe expansion (H 0 ) for each method, provide some discussions regarding the performance of each approach, and compare the results.