Séminaire / Seminar GReCO |
| « CMB spectra and weak gravitational lensing: are next-to-leading order corrections relevant for future observations? » |
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Giuseppe Fanizza |
| We investigate the weak lensing corrections to the CMB temperature and polarization anisotropies. We consider all the effects beyond the leading order: post-Born corrections, LSS corrections and, for the polarization anisotropies, the effect due to the change in the polarization direction between the emission at the source and the detection at the observer. We also show how the full next-to-leading order correction to the B-mode polarization is not negligible on small scales. By considering no primordial gravitational waves, B modes corrections due to rotation is comparable to cosmic variance for l = 3500, differently from what happens for all others spectra, whose corrections are always below that threshold. Moreover, the sum of all the effects is larger than cosmic variance at these multipoles, showing how higher-order lensing correction to B-modes polarization could be relevant even in considering a single multipole for l = 3500. The impact of these corrections for next generation experiments and the very good agreement with recent results from N-Body simulations underline how these effects are relevant for avoiding misinterpretation of observations. |
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lundi 20 mars 2017 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |