My research is mainly based on the subject of observational cosmology, more specifically on the study of the cosmic microwave background and the physics of galaxy clusters. For over a decade, I have been studying the Sunyaev-Zeldovich effect, with over 20 published research papers on the subject, which is a versatile trial for studying matter and baryon content in the universe. My current research focuses more on measuring the velocities of galaxies and galaxy clusters, and their masses using gravitational lensing. These topics directly address important scientific questions such as the nature of dark matter and dark energy.