Optimal and fast $\mathcal {E}/\mathcal {B}$ separation with a dual messenger field

Autor: Benjamin D. Wandelt, Doogesh Kodi Ramanah, Guilhem Lavaux
Přispěvatelé: Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Lagrange de Paris, Sorbonne Université (SU), Sorbonne Universités
Rok vydání: 2018
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2018, 476 (2), pp.2825-2834. ⟨10.1093/mnras/sty341⟩
Mon.Not.Roy.Astron.Soc.
Mon.Not.Roy.Astron.Soc., 2018, 476 (2), pp.2825-2834. ⟨10.1093/mnras/sty341⟩
ISSN: 1365-2966
0035-8711
DOI: 10.1093/mnras/sty341
Popis: International audience; We adapt our recently proposed dual messenger algorithm for spin field reconstruction and showcase its efficiency and effectiveness in Wiener filtering polarized cosmic microwave background (CMB) maps. Unlike conventional preconditioned conjugate gradient (PCG) solvers, our preconditioner-free technique can deal with high-resolution joint temperature and polarization maps with inhomogeneous noise distributions and arbitrary mask geometries with relative ease. Various convergence diagnostics illustrate the high quality of the dual messenger reconstruction. In contrast, the PCG implementation fails to converge to a reasonable solution for the specific problem considered. The implementation of the dual messenger method is straightforward and guarantees numerical stability and convergence. We show how the algorithm can be modified to generate fluctuation maps, which, combined with the Wiener filter solution, yield unbiased constrained signal realizations, consistent with observed data. This algorithm presents a pathway to exact global analyses of high-resolution and high-sensitivity CMB data for a statistically optimal separation of $$\mathcal {E}$$ and $$\mathcal {B}$$ modes. It is therefore relevant for current and next-generation CMB experiments, in the quest for the elusive primordial $$\mathcal {B}$$-mode signal.
Databáze: OpenAIRE