Résumé / Abstract Journal-club_Doctorants

Journal-club Doctorants / Journal-club PhD students

« Weak-lensing high order statistics »

Matteo Rizzato
Institut d'Astrophysique de Paris (Paris, France)

During my presentation I will explore the gain in performance for the Euclid mission by combining weak lensing power spectrum and bispectrum. I will show that the gain in information content we can achieve from higher order correlation functions is of about 40% compared to the two point statistics.

Correctly combining these two probes is challenging for different reasons. From the theoretical point of view, we need to model the non linear scales of dark matter clustering for which analytical approaches do not meet the required precision. Secondly, Euclid will detect the position of the sources in 10 topographic bins through the photometric survey. Therefore, for properly exploit all these information, remarkably big covariance matrices need to be computed and manipulated.

I developed a tool capable to perform these computations efficiently through the simplification of the statistics and exploiting super computers. In particular, it allowed to explore the impact of the unknowns in the theory in terms of parameters forecast where the halo model has been used to compute the spectra up to angular scales of l = 5000.
vendredi 8 février 2019 - 16:00
Salle Entresol Daniel Chalonge, Institut d'Astrophysique
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