Séminaire Univers / |
| « Probing dark energy with cosmic shear » |
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Nicolas Martinet |
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Understanding the accelerated expansion of the Universe is one of the most important challenges of modern cosmology. Thanks to the development of large dedicated surveys (Euclid, Rubin/LSST, Roman/WFIRST), weak-lensing cosmic shear offers the possibility to answer this question by constraining the dark energy equation of state (w). In this presentation, I will introduce cosmic shear and its application to current state-of-the-art surveys: the Kilo Degree Survey (KiDS) and the Dark Energy Survey (DES). I will discuss differences between these two surveys and how they impact the so-called cosmological tension observed between cosmic shear and cosmic microwave background constraints. I will then review future prospects to measure w with the Euclid satellite, focusing on the accurate modeling of systematic biases. Finally, I will show that these constraints can be significantly improved by resorting to weak-lensing mass map estimators that additionally probe the non-Gaussian part of the matter distribution.
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mardi 26 janvier 2021 - 11:15 Webinaire Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |