Simulated forecasts for primordial B-mode searches in ground-based
  experiments
  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 modelling of the foregrounds.
We find that S3 and S4-like experiments should be able to put constraints on
$r$ of the order $\sigma(r)=(0.5-1.0)\times10^{-2}$ and
$\sigma(r)=(0.5-1.0)\times10^{-3}$ 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 (AME) component would be clearly detectable by Stage-4
experiments.
