Correlations between 21 cm Radiation and the CMB from Active Sources

Abstract

Neutral hydrogen is ubiquitous, absorbing and emitting 21 cm radiation throughout much of the Universe's history. Active sources of perturbations, such as cosmic strings, would generate simultaneous perturbations in the distribution of neutral hydrogen and in the Cosmic Microwave Background (CMB) radiation from recombination. Moving strings would create wakes leading to 21 cm brightness fluctuations, while also perturbing CMB light via the Gott-Kaiser-Stebbins effect. This would lead to spatial correlations between the 21 cm and CMB anisotropies. Passive sources, like inflationary perturbations, predict no cross correlations prior to the onset of reionization. Thus, observation of any cross correlation between CMB and 21 cm radiation from dark ages would constitute evidence for new physics. We calculate the cosmic string induced correlations between CMB and 21 cm and evaluate their observability.

8 pages, 5 figures

References in corpus (8)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Fitting CMB data with cosmic strings and inflation
• The 21cm angular-power spectrum from the dark ages
• B-modes from Cosmic Strings
• A Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions
• Cross-correlation studies as a probe of reionization physics
• The effect of reionization on the CMB-density correlation
• The CMBR ISW and HI 21-cm Cross-correlation Angular Power Spectrum

Cited by in corpus (13)

• Seeking String Theory in the Cosmos
• Cosmic String constraints from WMAP and the South Pole Telescope
• The 21 cm Signature of Cosmic String Wakes
• Searching for Cosmic Strings in New Observational Windows
• Background reionization history from omniscopes
• LOFAR insights into the epoch of reionization from the cross power spectrum of 21cm emission and galaxies
• A Bayesian Framework for Cosmic String Searches in CMB Maps
• A Convolutional Neural Network For Cosmic String Detection in CMB Temperature Maps
• The 21cm Signature of a Cosmic String Loop
• Predicted Constraints on Cosmic String Tension from Planck and Future CMB Polarization Measurements
• Information Theoretic Bounds on Cosmic String Detection in CMB Maps with Noise
• A viable D-term hybrid inflation
• 21 cm Angular Spectrum of Cosmic String Loops