CONSTRAINTS ON FUNDAMENTAL COSMOLOGICAL PARAMETERS WITH UPCOMING REDSHIFTED 21 cm OBSERVATIONS

摘要

Constraints on cosmological parameters from upcoming measurements with the Mileura Wide-field Array Low Frequency Demonstrator (MWA LFD) of the redshifted 21 cm power spectrum are forecasted assuming a flat ACDM cosmology and assuming that the reionization of neutral hydrogen in the intergalactic medium occurs below a redshift of z = 8. We find that observations with the MWA LFD cannot constrain the underlying cosmology in this scenario. In principle, a similar experiment with a 10-fold increase in collecting area could provide useful constraints on the slope of the inflationary power spectrum, n_s, and the running of the spectral index, α_s, but these constraints are subject to the caveat that even a small reionization contribution could be confused with the cosmological signal. In addition to the redshifted 21 cm signal, we include two nuisance components in our analysis related to the systematics and astrophysical foregrounds present in low-frequency radio observations. These components are found to be well separated from the signal and contribute little uncertainty (< 30%) to the measured values of the cosmological model parameters.