The BINGO project

VII. Cosmological forecasts from 21 cm intensity mapping

¹ Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, PR China
e-mail: andrecosta@yzu.edu.cn
² Technische Universität München, Physik-Department T70, James-Franck-Straße 1, 85748 Garching, Germany
³ Divisão de Astrofísica, Instituto Nacional de Pesquisas Espaciais (INPE), São Jose dos Campos, SP, Brazil
⁴ School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, PR China
⁵ Instituto de Física, Universidade de São Paulo, CP 66.318, 05315-970 São Paulo, Brazil
⁶ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild Str. 1, 85741 Garching, Germany
⁷ Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
⁸ Department of Physics and Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
⁹ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
¹⁰ Unidade Acadêmica de Física, Universidade Federal de Campina Grande, R. Aprígio Veloso, 58429-900 Bodocongó, Campina Grande, PB, Brazil
¹¹ Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970 João Pessoa, Paraíba, Brazil
¹² Instituto de Física, Universidade de Brasília, Brasília, DF, Brazil
¹³ Centro de Gestão e Estudos Estratégicos – CGEE, SCS Quadra 9, Lote C, Torre C S/N Salas 401 – 405, 70308-200 Brasília, DF, Brazil
¹⁴ Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS), Daejeon 34126, Korea

Received: 25 March 2021
Accepted: 11 October 2021

Abstract

Context. The 21 cm line of neutral hydrogen (H I) 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 (LSS) observations with different systematics, and thus it will be used to improve our understanding of the Λ cold dark matter (ΛCDM) model. This will ultimately constrain our cosmological models, attack unresolved tensions, and test our cosmological paradigm. 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).

Aims. 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.

Methods. We used the 21 cm angular power spectra to extract cosmological information about the H I signal and the Fisher matrix formalism to study BINGO’s projected constraining power.

Results. 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 (DE) equation of state (EoS), respectively, within the wCDM model. Assuming a Chevallier–Polarski–Linder (CPL) parameterization, the EoS parameters have standard deviations given by σ_w0 = 0.30 and σ_wa = 1.2, which are improvements on the order of 30% with respect to Planck alone. We also compared BINGO’s fiducial forecast with future SKA measurements and found that, although it will not provide competitive constraints on the DE EoS, significant information about H I distribution can be acquired. We can access information about the H I density and bias, obtaining ∼8.5% and ∼6% precision, respectively, assuming they vary with redshift at three independent bins. BINGO can also help constrain alternative models, such as interacting dark energy and modified gravity models, improving the cosmological constraints significantly.

Conclusions. The fiducial BINGO configuration will be able to extract significant cosmological information from the H I distribution and provide constraints competitive with current and future cosmological surveys. It will also help in understanding the H I physics and systematic effects.