Cosmological constraints on the big bang quantum cosmology model

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 \( Ω_m = 0.3419 \pm 0.0065 \), results that are consistent with early-universe observations but exhibit a higher \( Ω_m \) compared to the $Λ$CDM model. In the case of a non-flat universe, $J$CDM favors a slightly curved geometry with \( Ω_k = 0.0154 \pm 0.0027 \), leading to \( H_0 = 69.13 \pm 0.56 \, \rm {km~s^{-1}~Mpc^{-1}} \) and \( Ω_m = 0.3477 \pm 0.0074 \). 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 $Λ$CDM, agrees excellently with late-time cosmology, it struggles to simultaneously match early-universe observations in a fully self-consistent manner.

Figures (4)

• Figure 1: One-dimensional marginalized probability distributions and two-dimensional confidence contour plots for the flat $J$CDM cosmological model, derived from the DESI+CMB, DESI+CMB+CC, and DESI+CMB+CC+SNIa datasets. Plots are presented for two acoustic horizon scale $r_{d}$ configurations: one defined in Eq. (\ref{['eq:rd']}) (referred to as the "unfixed” case, left panel) and the CMB derived value $r_{d} = 147.09\pm{0.29} ~\mathrm{Mpc}$ (referred to as the"fixed” case, right panel). Here, $H_0$ is given in units of $\rm km~s^{-1}~Mpc^{-1}$.
• Figure 2: One-dimensional marginalized probability distributions and two-dimensional confidence contour plots for the non-flat $J$CDM cosmological model, derived from the DESI+CMB, DESI+CMB+CC, and DESI+CMB+CC+SNIa datasets. Plots are presented for two acoustic horizon scale $r_{d}$ configurations: one defined in Eq. (\ref{['eq:rd']}) (referred to as the "unfixed” case, left panel) and the CMB derived value $r_{d} = 147.09\pm{0.29} ~\mathrm{Mpc}$ (referred to as the"fixed” case, right panel). Here, $H_0$ is given in units of $\rm km~s^{-1}~Mpc^{-1}$.
• Figure 3: One-dimensional marginalized probability distributions and two-dimensional confidence contour plots for the flat $\Lambda$CDM and $J$CDM cosmological models, derived from full combined datasets DESI+CMB+CC+SNIa. Plots are presented for two acoustic horizon scale $r_{d}$ configurations: one defined in Eq. (\ref{['eq:rd']}) (referred to as the "unfixed” case, left panel) and the CMB derived value $r_{d} = 147.09\pm{0.29} ~\mathrm{Mpc}$ (referred to as the"fixed” case, right panel). For comparison, results with and without the DESI BAO data at $z_{\rm eff}=0.51$ (shown as $z=0.51$) are also plotted. Here, $H_0$ is given in units of $\rm km~s^{-1}~Mpc^{-1}$.
• Figure 4: One-dimensional marginalized probability distributions and two-dimensional confidence contour plots for the non-flat $\Lambda$CDM and $J$CDM cosmological models, derived from full combined datasets DESI+CMB+CC+SNIa. Plots are presented for two acoustic horizon scale $r_{d}$ configurations: one defined in Eq. (\ref{['eq:rd']}) (referred to as the "unfixed” case, left panel) and the CMB derived value $r_{d} = 147.09\pm{0.29} ~\mathrm{Mpc}$ (referred to as the"fixed” case, right panel). For comparison, results with and without the DESI BAO data at $z_{\rm eff}=0.51$ (shown as $z=0.51$) are also plotted. Here, $H_0$ is given in units of $\rm km~s^{-1}~Mpc^{-1}$.