Unbiased Primordial Gravitational Wave Inference from the CMB with SMICA

2025/10/30 by Steier, Alexander, Ghosh, Shamik, Delabrouille, Jacques · 1 citation
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences

paper · doi:10.48550/arxiv.2510.26767

Abstract

The detection of primordial gravitational waves in Cosmic Microwave Background B-mode polarization observations requires accurate and robust subtraction of astrophysical contamination. We show, using a blind Spectral Matching Independent Component Analysis, that it is possible to infer unbiased estimates of the primordial B-mode signal from ground-based observations of a small patch of sky even for highly complex foreground contamination. This work, originally performed in the context of configuration studies for a future CMB-S4 observatory, is highly relevant for the analysis of observations by the current generation of CMB experiments.

Citations

• The Simons Observatory: Assessing the Impact of Dust Complexity on the Recovery of Primordial B-modes
• Full-sky Models of Galactic Microwave Emission and Polarization at Sub-arcminute Scales for the Python Sky Model
• CMB-S4: Foreground-Cleaning Pipeline Comparison for Measuring Primordial Gravitational Waves
• BlackJAX: Composable Bayesian inference in JAX
• PICO: Probe of Inflation and Cosmic Origins
• The Python Sky Model: software for simulating the Galactic microwave sky

Cited by

• A Generative Reconstruction of Low-ℓ CMB B-Mode Signal using Reverse Diffusion in Deep Learning

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