Component separation for future CMB B-mode satellites

Understand

Next-generation CMB satellite concepts (LiteBIRD, CORE, PIXIE, PICO) are being proposed to detect the primordial CMB B-mode polarization at large angular scales in the sky for tensor-to-scalar ratio values of ${r \lesssim 10^{-3}}$.

• Yet undetected, primordial CMB B-modes will provide the unique signature of the primordial gravitational waves of quantum origin predicted by inflation.
• We present recent forecasts on the detection of the primordial CMB B-modes in the presence of astrophysical foregrounds and gravitational lensing effects, in the context of the proposed CMB space mission CORE.
• We also discuss the problem of foregrounds and component separation for the search for primordial B-modes, and highlight specific challenges in this context: frequency range, spectral degeneracies, foreground modelling, spectral averaging effects.