Searches for inflationary gravitational wave signals in the CMB B-mode polarization are expected to reach unprecedented power over the next decade. A major difficulty in these ongoing searches is that Galactic foregrounds such as dust can easily mimic inflationary signals. Though typically foregrounds are separated from primordial signals using the foregrounds' different frequency dependence, in this talk I’ll discuss the extent to which the galactic dust B-modes' statistical anisotropy can be used to distinguish them from inflationary B-modes. I will present the results of our new estimator applied to simulated data-sets appropriate for upcoming CMB experiments, showing that we can detect residual dust levels corresponding to r~0.001 at 2 sigma for CMB-S4 noise levels. I’ll also outline how anisotropy statistics can be used to construct an estimate of the dust B-mode map, which could potentially be used to clean the B-mode sky.

Should you wish to order lunch, you may do so here by 10am on Thursday.