Cosmological constraints on the big bang quantum cosmology model

TL;DR

This paper constrains the JCDM cosmology model, which incorporates the trace of the Schouten tensor as dark energy, using diverse cosmological data, and discusses its implications for the Hubble tension and universe geometry.

Contribution

It provides the first comprehensive constraints on the JCDM model from multiple datasets, highlighting its consistency with late-time data but challenges with early-universe observations.

Findings

JCDM yields H0 ≈ 67 km/s/Mpc in flat universe

In non-flat universe, JCDM favors slight positive curvature

JCDM aligns with late-time data but struggles with early-universe consistency

Abstract

The big bang quantum cosmology model introduces the trace $J$ of the Schouten tensor as a form of dynamic dark energy. Together with cold dark matter, these components form the so-called $J$CDM cosmology model, proposed by M.H.P.M. van Putten (J. High Energy Astrophys., 45, 2025, 194), which offers a potential resolution to the Hubble tension. We derive the constraints on the $J$CDM cosmology model, utilizing early- and late-time cosmological data including cosmic microwave background (CMB), baryon acoustic oscillations (BAO) released by the Dark Energy Spectroscopic Instrument (DESI), cosmic chronometers (CC), and type Ia supernovae (SNIa). For a flat universe, the $J$CDM model yields \( H_0 = 66.95 \pm 0.51 \, \rm{km~s^{-1}~Mpc^{-1}} \) and \( \Omega_m = 0.3419 \pm 0.0065 \), results that are consistent with early-universe observations but exhibit a higher \( \Omega_m \) compared to the $\Lambda$CDM model. In the case of a non-flat universe, $J$CDM favors a slightly curved geometry with \( \Omega_k = 0.0154 \pm 0.0027 \), leading to \( H_0 = 69.13 \pm 0.56 \, \rm {km~s^{-1}~Mpc^{-1}} \) and \( \Omega_m = 0.3477 \pm 0.0074 \). The increase in \( H_0 \) in the non-flat scenario suggests a geometric degeneracy between spatial curvature and \( H_0 \). We also investigate the internal inconsistencies present in DESI data and evaluate their impacts on cosmological parameter constraints. Our analysis shows that while the $J$CDM model, which is constructed from first principles without free parameters beyond those of $\Lambda$CDM, agrees excellently with late-time cosmology, it struggles to simultaneously match early-universe observations in a fully self-consistent manner.