PRIMORDIAL MAGNETIC FIELDS WITH THE WMAP AND PLANCK SATELLITE EXPERIMENTS

We present a study of Faraday rotation of the Cosmic Microwave Background (CMB) polarization anisotropies by a large scale primordial magnetic eld (PMF) present at the time of decoupling. We assume weak intensity for the PMF, of the order of a nG nowadays, and tight coupling between photons, electrons and baryons around recombination. Under these hypotheses and considering no tensor perturbations, the equations of evolution of the CMB polarization lead to the direct generation of B polarization modes from the E modes generated by scalar perturbations. We are able to produce simulated CMB maps including this eect for a wide range of geometries of the PMF. From these simulations we extract the modied polarization angular power spectra and the results are compared to an analytic approach showing that our hypothesis leads to the same order of magnitude signature on the CMB C BB spectrum. Finally, we obtain an upper limit on the today intensity of the PMF, B0 < 27 nG (95% CL), by comparing our models to the C TE ‘ spectrum measured by WMAP.