DR. ADITYA ROTTI

CMB polarization analysis is conventionally carried out using harmonic space methods making the definitions of E and B modes fairly obscure. In the first part of his talk the speaker will describe a practical real space method for evaluating the scalar E and B mode maps from Stokes parameters Q/U on the sphere. This real space method will elucidate the nature of E and B modes and their non-local dependence on the Stokes parameters. He will argue that it is possible to think of Stokes parameters as some complex charge, which radiates a spin-0 complex scalar field, the real part of which corresponds to E-modes and the imaginary part to the B-modes of CMB polarization. He will briefly touch upon the issue of E to B leakage due to incomplete sky coverage and how one may circumvent this issue using this real space method. In the second part of his talk the speaker will discuss how isotropy tests can be a powerful diagnostic for assessing foreground contamination with emphasis on the B-modes of CMB polarization maps. He will present results from his analysis carried out on Planck 353GHz polarization maps.