Cosmological Analysis using Panstarrs data: Hubble Constant and Direction Dependence

TL;DR

This study analyzes Panstarrs1 supernova data to investigate the Hubble tension and potential anisotropy, finding persistent tension and no evidence of preferred cosmic direction, while revealing non-Gaussian errors.

Contribution

It applies Bayesian and Extreme Value theory methods to supernova data, providing new insights into Hubble constant measurements and isotropy assumptions.

Findings

Hubble tension remains unresolved with this data.

No significant direction dependence detected.

Errors are non-Gaussian in nature.

Abstract

Hubble tension and the search for preferred direction are two crucial unresolved issues in modern cosmology. Different measurements of the Hubble constant provide significantly different values, and this is known as the Hubble tension. The cosmological principle assumes that the universe is homogeneous and isotropic; however, deviations from the isotropy have often been observed. We apply the Bayesian tools and the Extreme Value theory dependent statistic to address the above issues. These techniques have been applied to the Panstarrs1 type Ia supernovae data. Our analysis for Hubble constant does not reject the Hubble tension. However, our value is smaller than that of the SHoES program and agrees with the CCHP value. Extreme value theory-based analysis indicates that the data does not show direction dependence. As a byproduct of our technique, we show that the errors in the data are non-Gaussian in nature.