Cosmology with the Kilo-Degree Survey

Abstract: I will present the recent cosmological analyses of weak gravitational lensing observations from the Kilo-Degree Survey (KiDS-1000), with redshift-space galaxy clustering observations from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing observations from the overlap between KiDS-1000, BOSS and the spectroscopic 2-degree Field Lensing Survey (2dFLenS). I will summarise the methodology and discuss the cosmological constraints, both within the the standard model of cosmology of a spatially flat Universe filled with cold dark matter and dark energy, and several extensions thereof. These results are then put in the context of the S8 tension: the disagreement between measurements of the cosmic microwave background by Planck and late-time analyses, such as ours, on how strongly matter in the Universe is clustered.