Absorption in the 21 cm Hydrogen Line at $z>10$ as a Sensitive Tool for the Construction of a Cosmological Model on Small Scales

Abstract

The cosmic microwave background absorption intensity in the 21 cm line of neutral hydrogen in the presence of additional power in the form of a "bump" in the spectrum of cosmological density perturbations is calculated. The main absorption-amplifying effect is the earlier birth of the first stars forming an ultraviolet radiation background. This radiation reduces the spin temperature of neutral hydrogen and, thus, amplifies the absorption in the 21 cm line. A comparison of various cosmological models (with and without a bump in the density perturbation spectrum) shows that it is possible to determine the probable position of the bump in the perturbation spectrum and, thus, to reconstruct the spectrum of cosmological perturbations on scales $k>1$~Mpc${}^{-1}$ from the position of the absorption frequency profile.

arXiv comment9 pages, 3 pages, typos are fixed

References in corpus (28)

• Planck 2013 results. XVI. Cosmological parameters
• The cosmological simulation code GADGET-2
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• 21-cm cosmology
• An excursion set model of hierarchical clustering: Ellipsoidal collapse and the moving barrier
• 21cmFAST: A Fast, Semi-Numerical Simulation of the High-Redshift 21-cm Signal
• Possible interaction between baryons and dark-matter particles revealed by the first stars
• The Global 21 Centimeter Background from High Redshifts
• Detecting the Earliest Galaxies Through Two New Sources of 21cm Fluctuations
• Wouthuysen-Field coupling strength and application to high-redshift 21 cm radiation
• Descending from on high: Lyman series cascades and spin-kinetic temperature coupling in the 21 cm line
• Redshifted 21 cm Emission From the Pre-Reionization Era I. Mean Signal and Linear Fluctuations
• Results from EDGES High-Band: I. Constraints on Phenomenological Models for the Global $21$ cm Signal
• Questions on calculation of primordial power spectrum with large spikes: the resonance model case
• The Most Massive Galaxies and Black Holes Allowed by $\Lambda$CDM
• Reionization after JWST: a photon budget crisis?
• Large-Scale Structure Shocks at Low and High Redshifts
• Results from EDGES High-Band: III. New Constraints on Parameters of the Early Universe
• Astrophysical Constraints from the SARAS3 non-detection of the Cosmic Dawn Sky-Averaged 21-cm Signal
• Alleviating the need for exponential evolution of JWST galaxies in 10${}^{10}{M}_{\odot }$ haloes at $z>10$ by a modified $\Lambda$CDM power spectrum
• Results from EDGES High-Band: II. Constraints on Parameters of Early Galaxies
• Heating of the intergalactic medium due to structure formation
• Excess of high-$z$ galaxies as a test for bumpy power spectrum of density perturbations
• Inner structure of dark matter halos at high $z$ in cosmological models with non-power-law primordial spectra
• Cascade Relaxation of the Gravitating Vacuum as a Generator of the Evolving Universe
• Global 21 cm signal: a promising probe of primordial features