Probing the dark Universe with weak lensing effects

Weak lensing (WL) effects are recognized as one of the most powerful probes in cosmological studies. It is, however, a difficult task to extract cosmological information fully and accurately from WL data. The challenges are two parts, one related to observational measurements, and the other for statistical analyses. In this talk, I will focus on the second part and discuss WL peak analyses and their complementary power to the cosmic shear correlation studies. I will present the cosmological constraints on the matter content of the Universe and on the modified gravities derived from our WL peak analyses with CFHT Stripe 82 and CFHTLenS observations. I will end with a discussion about our on-going efforts to improve our peak model for future precision WL studies.