KiDS-1000 Cosmology: Constraints beyond flat ΛCDM

We present constraints on extensions to the standard cosmological model of a spatially flat Universe governed by general relativity, a cosmological constant (Λ), and cold dark matter (CDM) by varying the spatial curvature Ω K , the sum of the neutrino masses ∑ m ν , the dark energy equation of state parameter w , and the Hu-Sawicki f ( R ) gravity f R 0 parameter. With the combined 3 × 2 pt measurements of cosmic shear from the Kilo-Degree Survey (KiDS-1000), galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing from the overlap between KiDS-1000, BOSS, and the spectroscopic 2-degree Field Lensing Survey, we find results that are fully consistent with a flat ΛCDM model with Ω K = 0.011 −0.057 +0.054 , ∑ m ν