Research encompasses core areas of fundamental physics as well as interdisciplinary border areas. In the core areas, research focuses on elementary particle physics, the structure and evolution of the universe, and the properties of complex classical and quantum systems. The interdisciplinary border areas include environmental physics, bio- and medical physics as well as technical computer science. Research is located at four department institutes and the Heidelberg Centre for Astronomy. Apart from that, the research environment in Heidelberg is distinguished by a multitude of extra-university research institutions which are topically and personally closely connected to the department.