To test the xQML estimator, we generate CMB maps using the usual fiducial model, and add a non-zero EB spectrum given by {$ C_\ell^{EB} = c \cdot\sqrt{C_\ell^{EE} C_\ell^{BB}} $} where {$ c \in [0,...,1] $} is a correlation paramater.
Voir papier Planck birefringence : Planck intermediate results. XLIX. Parity-violation constraints from polarization data
mode-mode matrices are now of dimension [3*nbins, 3*nbins].
2.2 Results :
ns= 4
0.1 muK-arcmin
the red curve 'fisher' is not the fisher error but the mode-counting error (forget to correct).