Probing Quintessence using BAO imprint on the cross-correlation of weak lensing and post-reionization HI 21 cm signal

TL;DR

This paper explores constraining a thawing Quintessence dark energy model by using BAO imprints on the cross-correlation of 21-cm signals and weak lensing, achieving percent-level precision with SKA-like observations combined with other probes.

Contribution

It introduces a novel method of using BAO features in the cross-correlation of 21-cm and weak lensing data to constrain dark energy parameters.

Findings

Potential to measure $D_A$ and $H$ at a few percent level with SKA-1-Mid and weak lensing.

Constraints on Quintessence parameters improve significantly when combined with SN data.

Monte Carlo analysis yields specific bounds on model parameters.

Abstract

In this work we investigate the possibility of constraining a thawing Quintessence scalar field model for dark energy. We propose using the imprint of baryon acoustic oscillation (BAO) on the cross-correlation of post-reionization 21-cm signal and galaxy weak lensing convergence field to tomographically measure the angular diameter distance $D_A(z)$ and the Hubble parameter $H(z)$. The projected errors in these quantities are then used to constrain the Quintessence model parameters. We find that independent $600$hrs radio interferometric observation at four observing frequencies $916 $MHz, $650$ MHz, $520$ MHz and $430 $MHz with a SKA-1-Mid like radio telescope in cross-correlation with a deep weak lensing survey covering half the sky may measure the binned $D_A$ and $H$ at a few percent level of sensitivity. The Monte Carlo analysis for a power law thawing Quintessence model gives the $1-\sigma$ marginalized bounds on the initial slope $\lambda_i$,dark energy density parameter $\Omega_{\phi 0}$ and the shape of the potential $\Gamma$ at 8.63%, 10.08% and 9.75% respectively. The constraints improve to 7.66%, 4.39% and 5.86% respectively when a joint analysis with SN and other probes is performed.