The High-Redshift Neutral Hydrogen Signature of an Anisotropic Matter Power Spectrum

Understand

An anisotropic power spectrum will have a clear signature in the 21cm radiation from high-redshift hydrogen.

• We calculate the expected power spectrum of the intensity fluctuations in neutral hydrogen from before the epoch of reionization, and predict the accuracy to which future experiments could constrain a quadrupole anisotropy in the power spectrum.
• We find that the Square Kilometer Array will have marginal detection abilities for this signal at z~17 if the process of reionization has not yet started; reionization could enhance the detectability substantially.
• Pushing to higher redshifts and higher sensitivity will allow highly precise (percent level) measurements of anisotropy.