Simulated forecasts for primordial B-mode searches in ground-based experiments

Journal article

Detecting the imprint of inflationary gravitational waves on the B-mode polarization of the cosmic microwave background (CMB) is one of the main science cases for current and next-generation CMB experiments. In this work we explore some of the challenges that ground-based facilities will have to face in order to carry out this measurement in the presence of galactic foregrounds and correlated atmospheric noise. We present forecasts for stage-3 (S3) and planned stage-4 (S4) experiments based on the analysis of simulated sky maps using a map-based Bayesian foreground-cleaning method. Our results thus consistently propagate the uncertainties on foreground parameters such as spatially varying spectral indices, as well as the bias on the measured tensor-to-scalar ratio r caused by an incorrect modeling of the foregrounds. We find that S3 and S4-like experiments should be able to put constraints on r of the order σ(r) = (0.5–1.0) × 10^−2 and σ(r) = (0.5–1.0) × 10^−3 respectively, assuming instrumental systematic effects are under control. We further study deviations from the fiducial foreground model, finding that, while the effects of a second polarized dust component would be minimal on both S3 and S4, a 2% polarized anomalous dust emission component would be clearly detectable by stage-4 experiments.

Authors: Alonso, D; Dunkley, J; Næss, S; Thorne, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review D
• Volume: 95
• Issue: 4
• Pages: 043504
• Publication date: 2017-02-01
• DOI: 10.1103/PhysRevD.95.043504
• EISSN: 2470-0029
• ISSN: 2470-0010