Reionization and Cosmology with 21 cm Fluctuations

TL;DR

This paper reviews how 21 cm line observations can illuminate the epoch of reionization, galaxy formation, and cosmology from redshifts 1 to 4, highlighting recent theoretical and observational advances.

Contribution

It synthesizes recent progress in understanding 21 cm fluctuations for reionization and cosmology, emphasizing the potential of upcoming instruments and techniques.

Findings

Expected 21 cm signal characteristics during reionization

Capabilities of first-generation 21 cm instruments

Potential for constraining dark energy parameters

Abstract

Measurement of the spatial distribution of neutral hydrogen via the redshifted 21 cm line promises to revolutionize our knowledge of the epoch of reionization and the first galaxies, and may provide a powerful new tool for observational cosmology from redshifts 1<z<4 . In this review we discuss recent advances in our theoretical understanding of the epoch of reionization (EoR), the application of 21 cm tomography to cosmology and measurements of the dark energy equation of state after reionization, and the instrumentation and observational techniques shared by 21 cm EoR and post reionization cosmology machines. We place particular emphasis on the expected signal and observational capabilities of first generation 21 cm fluctuation instruments.