Amir Hajian
Inter-Univ. Center Astron. Astroph. (IUCAA) (Pune, Inde)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « Statistical Isotropy in the WMAP Data: Bipolar Power Spectrum Analysis » |
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Amir Hajian |
| Statistical properties of a CMB anisotropy sky are usually assumed to be invariant under the rotations of the sky. This assumption simplifies many problems in CMB and allows us to use the well known angular power spectrum for model comparisons with no loss in the information. However there are certain cases (eg. non-trivial cosmic topology, presence of primordial magnetic fields, or observational artifacts such as non-circular beam or residuals from foregrounds) which break down the above symmetries. We introduce the Bipolar Power Spectrum (BiPS) which is a general way of studying a random field on a sphere. BiPS is shown to be sensitive to the above effects and that makes it a good tool to search for the topology of our universe or residuals from observational artifacts in a CMB anisotropy map. In this talk, the application of BiPS to the WMAP data will be presented. |
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vendredi 17 septembre 2004 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |