Constraining dark energy using the cross correlations of weak lensing
with post-reionization probes of neutral hydrogen
(2020)cite arxiv:2010.05816Comment: Submitted. Comments are welcome.Abstract
We investigate the prospects of detecting the cross correlation of
weak-lensing convergence field with the large scale tracers of the underlying
dark matter distribution in the post-reionization epoch. The cross-correlation
is then used to constrain dark energy equation of state (EoS) for models with a
time evolving dark energy.We study the cross-correlation angular power spectrum
of the weak-lensing field with the Lyman-alpha forest and the redshifted HI 21
cm signal from the post reionization epoch. The angular power spectra is
expressed as a line of sight average over the tomographic slices. We find that
on using multiple 400 hrs observation with an extended GMRT like instrument or
with a quasar (QSO) density of 16 deg^-2 the cross-correlation with
weak-lensing convergence field covering half the sky can be detected at a very
high SNR (>20). The cross-correlation of weak-lensing with Lyman-alpha forest
allows the $1-\sigma$ errors on the dark energy EoS parameters for different
parametrizations to be constrained at a level of precision comparable to
combined Planck+SNIa+BAO+HST projections.The 21-cm weak-lensing
cross-correlation is found to provide strong constraints on the present value
of the dark energy EoS parameter at 2% for the 7CPL model.The constraints on
w_a is comparable (~ 10%) for models other than the 7CPL model. We also find
that the CPL parametrization may not be the best constrained parametrization
for dark energy evolution. The cross-correlation of weak-lensing with the the
post-reionization probes of neutral hydrogen thus holds the potential to give
us valuable understanding about the nature of evolving dark energy.
Description
Constraining dark energy using the cross correlations of weak lensing with post-reionization probes of neutral hydrogen