Large-angle Polarization of the Cosmic Microwave Background Radiation and Reionization

We discuss the effect of matter reionization on the large-angular-scale anisotropy and polarization of the cosmic microwave background radiation (CMBR) in the standard CDM model. We separate three cases in which the anisotropy is induced by pure scalar, pure tensor, and mixed metric perturbations respectively. It is found that, if reionization occurs early enough, the polarization can reach a detectable level of sequentially $6\%$, $9\%$, and $6.5\%$ of the anisotropy. In general, a higher degree of polarization implies a dominant contribution from the tensor mode or reionization at high redshift. Since early reionization will suppress small-scale CMBR anisotropies and polarizations significantly, measuring the polarization on few degree scales can be a direct probe of the reionization history of the early universe.Comment: Changes in the revised version: 1. Below Eq. (2), we demonstrate the method of our numerical work, by adding the evolution equations for the Legendre coefficents for both the scalar and tensor mode pertubations. 2. Below Eq. (9), we added a paragraph on discussing the basis we employed in computing the polarization correlation function. 3. In Sec. 4, we have rewritten the first and second paragraphs, where we illustrate how to the explain the discrepancies with the previous wor

EDUCATION

RESEARCH AREAS Computational social choice; preference aggregation; complexity of elections; cooperative game theory; algorithms and complexity, approximation algorithms. I am particularl

EDUCATION

RESEARCH AREAS Computational social choice; preference aggregation; complexity of elections; cooperative game theory; algorithms and complexity, approximation algorithms. I am particularly interested in ideas, concepts, and research spanning and linking all these areas

EDUCATION

RESEARCH AREAS Computational social choice; preference aggregation; complexity of elections; cooperative game theory; algorithms and complexity, approximation algorithms. I am particularly interested in ideas, concepts, and research spanning and linking all these areas