Cosmological constraints from the EFT power spectrum and tree-level bispectrum of 21 cm intensity maps

• DOI: 10.1016/j.dark.2024.101530
• Publication Date: 2024-05-16T17:41:32Z
• Authors: Liantsoa F. Randr...; Dionysios Karagia...; Roy Maartens
• Keywords: Bispectrum; Cosmology and Nongalactic Astrophysics (astro-ph.CO); Effective field theory; 500; FOS: Physical sciences; General Relativity and Quantum Cosmology (gr-qc); 7. Clean energy; 520; General Relativity and Quantum Cosmology; Cosmology; Fisher matrix; Power spectrum; 13. Climate action; Astrophysics - Cosmology and Nongalactic Astrophysics

We explore the information content of 21cm intensity maps in redshift space using the 1-loop Effective Field Theory power spectrum model and the bispectrum at tree level. The 21cm signal contains signatures of dark matter, dark energy and the growth of large-scale structure in the Universe. These signatures are typically analyzed via the 2-point correlation function or power spectrum. However, adding the information from the 3-point correlation function or bispectrum will be crucial to exploiting next-generation intensity mapping experiments. The bispectrum could offer a unique opportunity to break key parameter degeneracies that hinder the measurement of cosmological parameters and improve on the precision. We use a Fisher forecast analysis to estimate the constraining power of the HIRAX survey on cosmological parameters, dark energy and modified gravity.<br/>16 + 4 pages, "Minor corrections, main results unchanged. Version accepted by Phys. Dark Univ"<br/>