A Review of Cosmological Weak Lensing in 2019

Mittwoch, 4. Dezember 2019, 14:00 - 15:30
Veranstaltungsort* Library
 
Over the last few years, cosmological estimates made with the weak gravitational lensing of large scale structure (so-called cosmic shear) have moved into the regime where inference is limited primarily by systematic, rather than statistical, uncertainties. Working within such a regime means that additional survey data is unlikely to cause considerable reductions to the cosmological estimate uncertainties; a significant problem for a field whose current goals include understanding and explaining a ~2-3 sigma discrepancy between cosmological estimates observed at low- and high-redshift. This has motivated the cosmic shear community to scrutinise even the most fundamental methods and assumptions of their craft, and to construct new methods of analysis that may be able to tease out possible biases within their work. In this talk, I aim to introduce and discuss the methods (and possible biases therein) which are fundamental to cosmology with cosmic shear. Beginning with an introduction to cosmic shear, I will then discuss the most recent cosmological results from 3 cosmic shear surveys: KiDS, DES, and HSC. I will then explore some of the most recent developments in the field, and discuss how these developments are likely to influence the observed tensions between cosmic shear and Planck, and impact our understanding of cosmology as a whole.      


: Dr. Angus Wright, Ruhr-Universität Bochum