Moment expansion of polarized dust SED: a new path towards capturing the CMB $B$-modes with $\textit{LiteBIRD}$

Understand

Characterizing the polarized dust emission from our Galaxy will be decisive for the quest for the Cosmic Microwave Background (CMB) primordial $B$-modes.

• The incomplete modelling of its potentially complex spectral properties could lead to biases in the CMB polarization analyses and to a spurious detection of the tensor-to-scalar ratio $r$.
• It is crucial for future surveys like the $LiteBIRD$ satellite, which aims at constraining the primordial signal leftover by Inflation with an accuracy on $r$ of the order 1e-3.
• Variations of the dust properties along and between lines of sight lead to distortions of the spectral energy distribution (SED) that can not be easily anticipated by standard component separation methods.