Model-Independent Reionization Observables in the CMB
Abstract
We represent the reionization history of the universe as a free function in redshift and study the potential for its extraction from CMB polarization spectra. From a principal component analysis, we show that the ionization history information is contained in 5 modes, resembling low-order Fourier modes in redshift space. The amplitude of these modes represent a compact description of the observable properties of reionization in the CMB, easily predicted given a model for the ionization fraction. Measurement of these modes can ultimately constrain the total optical depth, or equivalently the initial amplitude of fluctuations to the 1% level regardless of the true model for reionization.
Keywords
Cite
@article{arxiv.astro-ph/0303400,
title = {Model-Independent Reionization Observables in the CMB},
author = {Wayne Hu and Gilbert P. Holder},
journal= {arXiv preprint arXiv:astro-ph/0303400},
year = {2011}
}
Comments
4 pages, 5 figures, submitted to PRD (rapid communications)