The BINGO Project VII: Cosmological Forecasts from 21cm Intensity Mapping

TL;DR

The paper evaluates BINGO's potential to constrain cosmological parameters using 21cm intensity mapping, showing significant improvements when combined with Planck data and analyzing various instrument configurations.

Contribution

It provides the first detailed cosmological forecasts for BINGO, assessing its capabilities and systematic effects in constraining key cosmological parameters.

Findings

BINGO combined with Planck improves H0 and dark energy EoS constraints by an order of magnitude.

Fiducial BINGO configuration can measure HI density and bias with 8.5% and 6% precision.

Instrument configuration impacts forecast precision, emphasizing the importance of systematics control.

Abstract

The 21cm line of neutral hydrogen (HI) opens a new avenue in our exploration of the structure and evolution of the Universe. It provides complementary data to the current large-scale structure observations with different systematics, and thus it will be used to improve our understanding of the $\Lambda$CDM model. Among several radio cosmological surveys designed to measure this line, BINGO is a single-dish telescope mainly designed to detect baryon acoustic oscillations (BAOs) at low redshifts ($0.127< z<0.449$). Our goal is to assess the fiducial BINGO setup and its capabilities of constraining the cosmological parameters, and to analyze the effect of different instrument configurations. We used the Phase 1 fiducial configuration of the BINGO telescope to perform our cosmological forecasts. In addition, we investigated the impact of several instrumental setups, taking into account some instrumental systematics, and different cosmological models. Combining BINGO with Planck temperature and polarization data, the projected constraint improves from a $13\%$ and $25\%$ precision measurement at the $68\%$ confidence level with Planck only to $1\%$ and $3\%$ for the Hubble constant and the dark energy equation of state (EoS), respectively, within the wCDM model. Assuming a Chevallier-Polarski-Linder parameterization, the EoS parameters have standard deviations given by $\sigma_{w_0} = 0.30$ and $\sigma_{w_a} = 1.2$, which are improvements on the order of $30\%$ with respect to Planck alone. Also, we can access information about the HI density and bias, obtaining $\sim 8.5\%$ and $\sim 6\%$ precision, respectively, assuming they vary with redshift at three independent bins. The fiducial BINGO configuration will be able to extract significant cosmological information from the HI distribution and provide constraints competitive with current and future cosmological surveys. (Abridged)