High precision modeling of polarized signals: Moment expansion method generalized to spin-2 fields

Understand

The modeling and removal of foregrounds poses a major challenge to searches for signals from inflation using the cosmic microwave background (CMB).

• In particular, the modeling of CMB foregrounds including various spatial averaging effects introduces multiple complications that will have to be accounted for in upcoming analyses.
• In this work, we introduce the generalization of the intensity moment expansion to the spin-2 field of linear polarization: the spin-moment expansion.
• Within this framework, moments become spin-2 objects that are directly related to the underlying spectral parameters and polarization angle distribution functions.