Self-Calibration of CMB Polarization Experiments

Understand

Precision measurements of the polarization of the cosmic microwave background (CMB) radiation, especially experiments seeking to detect the odd-parity "B-modes", have far-reaching implications for cosmology.

• To detect the B-modes generated during inflation the Flux response and polarization angle of these experiments must be calibrated to exquisite precision.
• While suitable flux calibration sources abound, polarization angle calibrators are deficient in many respects.
• Man-made polarized sources are often not located in the antenna's far-field, have spectral properties that are radically different from the CMB's, are cumbersome to implement and may be inherently unstable over the (long) duration these searches require to detect the faint signature of the inflationary epoch.