Séminaire / Seminar GReCO |
| « CMB Polarization: a line-of-sight approach and applications » |
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R. Abramo |
| We show how cosmic microwave background polarization can be computed in a line-of-sight, causal approach along our past light-cone. This description has the advantage of separating the initial conditions of the radiation field from the sources of Thomson/Compton scattering. We then discuss two applications of this method: first, we describe how a survey of the polarization induced by Compton scattering in galaxy clusters can be used to make a full spatial reconstruction of the primordial (z~1089) matter distribution inside our surface of last scattering. This polarization tomography can yield a spatial map of the initial state of the Universe just as gravitational collapse was beginning to drive structure formation. Second, we describe the full polarization signal on Earth in terms of linear physics and the visibility function (i.e., optical depth) in real space along our past light-cone. This has many potential uses, as the visibility function can (and will) be obtained from 21cm (neutral H) maps of the Universe. |
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lundi 29 octobre 2007 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |