Eur. Phys. J. C (2023) 83: 671
https://doi.org/10.1140/epjc/s10052-023-11841-z

Regular Article - Theoretical Physics

Possible combinations of early and late time cosmologies through BAO scales

¹ Department of Physics, Gauhati University, 781014, Guwahati, India
² Department of Physics, Mangaldai College, 784125, Guwahati, India

^b chayanika.rabha@gmail.com

Received: 19 April 2023
Accepted: 16 July 2023
Published online: 27 July 2023

Abstract

The theoretical scenarios of early universe and late time accelerated expansion constitute an open problem in cosmology. Relative Baryon Acoustic Oscillation (BAO) scales measured by 6dFGS, $\mathrm{S}DSS+2dFGRS$, BOSS DR11 Ly$\alpha$ and BOSS DR11 QSO Ly$\alpha$ are used to investigate the parameter spaces of combinations of pre-recombination physics and late time cosmology. For pre-recombination physics we fix ${\mathrm{N}}_{\mathit{eff}}=3$ and 4 and incorporate an Early Dark Energy (EDE) component. For late time cosmologies we consider curved $\mathrm{\Lambda }$CDM model, Dynamical Dark Energy (DDE) model with CPL parameterisation (${\omega }_0,{\omega }_1$) of equation of state, Coupled Dark Energy (CDE) model with constant coupling and curved DGP brane-world scenario. Combination of a curved $\mathrm{\Lambda }$CDM (${\mathrm{\Omega }}_{\text{k}}\mathrm{\Lambda }$CDM) model with ${\mathrm{N}}_{\mathit{eff}}$-EDE cosmology is found to be possible. For DDE, the relative BAO scales are achievable through ${\omega }_1$ preferring the region ${\omega }_1<0$. For ${\mathrm{N}}_{\mathit{eff}}$-EDE-CDE, the BAO scales are generated for both dark energy-dark matter and dark matter-dark energy conversion, however with exceptionally large value of dark energy density parameter and constant equation of state with ${\omega }_0>-1$. Curved DGP cosmology (${\mathrm{\Omega }}_{\text{k}}$DGP) is found to join with $N_{\text{eff}}$-EDE cosmology through curvature parameter ${\mathrm{\Omega }}_{\mathrm{k}(0)}\in [-0.002,-0.1]$ and cross-over parameter ${\mathrm{\Omega }}_{{\mathrm{r}}_{\mathrm{c}}}\in [0.08,0.45]$. Cosmic ages are calculated for the derived parameters of ${\mathrm{\Omega }}_{\text{k}}\mathrm{\Lambda }$CDM, flat DDE and ${\mathrm{\Omega }}_{\text{k}}$DGP models and compared with the ages of few globular clusters available in literature. Curved cosmologies are found to be promising.