We present a joint cosmological analysis 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 ) .
This combination of large-scale structure probes breaks the degeneracies between cosmological parameters for individual observables , resulting in a constraint on the structure growth parameter S _ { 8 } = \sigma _ { 8 } \sqrt { \Omega _ { m } / 0.3 } = 0.766 ^ { +0.020 } _ { -0.014 } , that has the same overall precision as that reported by the full-sky cosmic microwave background observations from Planck .
The recovered S _ { 8 } amplitude is low , however , by 8.3 \pm 2.6 \% relative to Planck .
This result builds from a series of KiDS-1000 analyses where we validate our methodology with variable depth mock galaxy surveys , our lensing calibration with image simulations and null-tests , and our optical-to-near-infrared redshift calibration with multi-band mock catalogues and a spectroscopic-photometric clustering analysis .
The systematic uncertainties identified by these analyses are folded through as nuisance parameters in our cosmological analysis .
Inspecting the offset between the marginalised posterior distributions , we find that the S _ { 8 } -difference with Planck is driven by a tension in the matter fluctuation amplitude parameter , \sigma _ { 8 } .
We quantify the level of agreement between the CMB and our large-scale structure constraints using a series of different metrics , finding differences with a significance ranging between \sim 3 \sigma , when considering the offset in S _ { 8 } , and \sim 2 \sigma , when considering the full multi-dimensional parameter space .