Understanding the impact of Light cone effect on the EoR/CD 21cm power spectrum
Abstract
Redshifted HI 21cm signal from the cosmic dawn and epoch of reionization evolve considerably along the LoS. We study the impact of this evolution (so called the light cone effect) on the HI 21cm power spectrum. It is found that the LC effect has a significant impact on the 3D power spectrum and the change could be up to a factor of few. The LC effect is particularly strong during the cosmic dawn near the `peaks' and `dips' in the power spectrum when plotted with redshift. We also show that the 3D power spectrum, which could fully describe ergodic and periodic signal, losses out some information regarding the second order statistics of the signal as the EoR/CD 21cm signal is nonergodic and nonperiodic along the line of sight. We show that the multifrequency angular power spectrum (MAPS) ℓ (ν_1, ν_2) captures all the information regarding the second order statistics of the signal even in the presence of the LC effect.
 Publication:

Peering towards Cosmic Dawn
 Pub Date:
 May 2018
 DOI:
 10.1017/S1743921318000637
 Bibcode:
 2018IAUS..333...12D
 Keywords:

 Cosmology: Epoch of Reionization;
 Cosmic Dawn;
 21cm line;
 Theory & Simulations;
 Statistical analysis