Orateur
Description
Over the coming years cosmology will be transformed, with enormous amounts of new data being collected by Stage IV spectroscopic and photometric galaxy surveys: DESI, Euclid, Rubin, and Roman. Most of the high precision data these surveys provide are within the small-scale (nonlinear) regime, which is extremely difficult to model. This includes nonlinear modelling of dark matter and biased redshift space clustering, baryonic feedback, and intrinsic alignments. Modelling for beyond-LCDM models is particularly challenging, and inaccuracies can lead to false detections and tensions. In this talk, I will describe state-of-the-art modelling approaches for spectroscopic galaxy clustering and weak gravitational lensing, focusing on opportunities and challenges for Stage IV surveys aiming to detect or refute non-standard physics. I will also talk about recent analyses of existing clustering and lensing data (from BOSS, KiDS, and DES) with new theoretical methods and numerical tools.