Constraining Cosmological and Astrophysical Parameters with the Cosmic Star Formation History

TL;DR

This study investigates the cosmic star formation rate density as a new observational probe to improve constraints on cosmological parameters like Hubble constant, matter density, and dark energy properties, by combining it with existing data.

Contribution

It demonstrates that SFRD, when combined with BAO, SNIa, and BBN data, significantly tightens cosmological parameter constraints and reduces astrophysical uncertainties.

Findings

SFRD combined with BBN yields H0 = 65±11 km/s/Mpc with degeneracies.

Joint analysis with BAO and SNIa constrains H0 to 68.28±0.18 km/s/Mpc.

Reconstructed SFRD peaks at redshift z ≈ 2.6.

Abstract

Identifying new observational probes to constrain cosmological parameters has become an important goal in modern cosmology. In this work, we explore the potential of the cosmic star formation rate density (SFRD), compiled over the redshift range $z \in [0, 15]$, as a complementary probe of fundamental parameters, including $\Omega_{\rm m}$, $H_0$, and the dark energy equation-of-state parameter, $w$. Within the $\Lambda$CDM framework, SFRD combined with BBN data alone yields $H_0 = 65\pm11$ km\,s$^{-1}$\,Mpc$^{-1}$, reflecting significant degeneracies with astrophysical parameters. By jointly analyzing SFRD with recent BAO and Type Ia supernova (SNIa) data, these degeneracies are effectively broken, resulting in much tighter constraints, e.g., \texttt{SFRD + BBN} + \texttt{DESI-DR2} gives $H_0 = 68.28 \pm 0.18$ km\,s$^{-1}$\,Mpc$^{-1}$. We perform a statistical reconstruction of the SFRD as a function of redshift, finding a peak at $z_{\rm peak} = 2.600^{+0.114}_{-0.087}$ within $\Lambda$CDM. Our results demonstrate that combining SFRD with established cosmological probes not only improves constraints on cosmological parameters but also reduces uncertainties in astrophysical parameters governing star formation. We further extend the analysis to the $w$CDM model, highlighting the promise of SFRD as a robust complementary cosmological probe across different dark energy scenarios.