In my talk, I will present recent results on the structure of galaxy clusters and the constraints on cosmological parameters obtained via stacked weak lensing and peak statistics. By using the shear data from the CFHT Lensing Survey, we used stacked weak gravitational lensing to obtain new constraints on the mass-concentration relation of clusters at intermediate redshift, and to obtain a new accurate measurement of the halo bias. Successively, we proposed a new method to measure the cosmological parameters \sigma_8 (i.e., the rms fluctuation in the mass distribution on scales of 8/h Mpc) and \Omega_m by means of joint analysis of weak lensing and clustering. I will also discuss a novel use of peak statistics to constrain the parameters of the mass-concentration relation as well as cosmological parameters. Finally, I will discuss the science goals of three weak lensing surveys: VOICE and KiDS, two on-going VST surveys, and the future misson Euclid.
Giovanni Covone has studied as PhD student at University "Federico II" of Naples and at the MIT. He obtained his PhD in Physics from University "Federico II" of Naples in 2001. Then he worked as postodc at the National Telescope Galileo (Spain) until 2003,at the CNRS-Laboratoire d'Astrophysique de Marseille (France) until 2006, at the INAF-Capodimonte Observatory (Italy) until 2007.Since 2008, he is assistant professor at the Department of Physics of the University of Naples. His main research interests include strong and weak gravitational lensing, observational cosmology and the study of the dark matter properties. He is currently leading the survey VOICE at the VLT Survey Telescope, and he is member of the collaborations KiDS, Euclid and DarkSide.