Cosmological constraints from weak lensing: present measurements and future challengesy
Weak lensing is a powerful tool for cosmological inference. In this talk I will discuss two major applications, cosmic shear and galaxy-galaxy lensing, in the context of recent studies carried out together with my collaborators. In the first part I will discuss a technique to directly extract the matter power spectrum in different redshift bins from weak lensing measurements. I will show results from an application to state-of-the-art CFHTLenS data and discuss the constraints on cosmological parameters and neutrino mass. In the second part of my talk I will focus on the potentials and challenges of future large weak lensing surveys such as Euclid for cosmological constraints derived from galaxy cluster counts. For that accurate and precise cluster masses are paramount. In this context, I will discuss the impact of various sources of bias on weak lensing cluster mass estimates.