Cosmic Microwave Background (CMB) polarization refers to the patterns of polarization observed in the CMB radiation, which is the afterglow of the Big Bang and the oldest light in the universe. These patterns of polarization provide important information about the early universe’s conditions and evolution.
CMB polarization can be characterized by two main components: E-mode (electric mode) polarization and B-mode (magnetic mode) polarization. E-mode polarization is typically caused by the scattering of CMB photons by hot electrons, and it reveals information about the density variations in the early universe. B-mode polarization, on the other hand, arises due to the gravitational effects of density fluctuations, such as those caused by cosmic inflation, and can provide insights into the universe’s early expansion and its fundamental properties.
