Roland Walter's research focuses on the nature of astrophysical sources accelerating very high-energy particles, the origin of cosmic rays, and the use of intensity interferometry to study accretion disks around compact stars. Since 2009, Roland Walter has initiated and contributed to the Swiss coordination of activities linked to the CTA Cherenkov telescope network project. His main responsibility is the real-time processing of data from all the telescopes (equivalent to 1 million CD-ROMs per night). He is also leading the construction of an instrument to image a black hole in visible light with a resolution of one billionth of a degree.