KiDS-450: The tomographic weak lensing power spectrum and constraints on
  cosmological parameters
  We present measurements of the weak gravitational lensing shear power
spectrum based on $450$ sq. deg. of imaging data from the Kilo Degree Survey.
We employ a quadratic estimator in two and three redshift bins and extract band
powers of redshift auto-correlation and cross-correlation spectra in the
multipole range $76 \leq \ell \leq 1310$. The cosmological interpretation of
the measured shear power spectra is performed in a Bayesian framework assuming
a $\Lambda$CDM model with spatially flat geometry, while accounting for small
residual uncertainties in the shear calibration and redshift distributions as
well as marginalising over intrinsic alignments, baryon feedback and an
excess-noise power model. Moreover, massive neutrinos are included in the
modelling. The cosmological main result is expressed in terms of the parameter
combination $S_8 \equiv \sigma_8 \sqrt{\Omega_{\rm m}/0.3}$ yielding $S_8 = \
0.651 \pm 0.058$ (3 z-bins), confirming the recently reported tension in this
parameter with constraints from Planck at $3.2\sigma$ (3 z-bins). We
cross-check the results of the 3 z-bin analysis with the weaker constraints
from the 2 z-bin analysis and find them to be consistent. The high-level data
products of this analysis, such as the band power measurements, covariance
matrices, redshift distributions, and likelihood evaluation chains are
available at http://kids.strw.leidenuniv.nl/
