The KiDS-450 weak-lensing power spectrum, neutrinos, and baryons

Fabian Koehlinger

I will present first results from our measurement of the weak-lensing power spectrum from 450 square degrees of shear data from the Kilo-Degree Survey (KiDS). We use a quadratic estimator for the extraction of the lensing power spectrum in several tomographic redshift bins in terms of adjustable band powers in multipole space.We optimize the extraction of the lensing power spectrum in order to enhance distinct features in multipole space and their redshift-dependence such as imprinted, for example, by massive neutrinos and baryon feedback.Based on the extracted lensing power spectrum we derive constraints on neutrinos, baryon feedback, and cosmological parameters. We find our constraint on the parameter combination best constrained by lensing, i.e. S8, to be in tension with the CMB constraint from Planck.