After a few years on the MPIfR staff, he moved to the University of California, Berkeley before joining the University of Manchester, where he became Professor of Astrophysics in 2006. In 2009 he was appointed Director back at the MPIfR.
His main research interest is the study of fundamental physics using radio astronomy, in particular radio pulsars. He was a member of the team that received the Descartes Prize of the European Union in 2005, and was distinguished with the Marcel-Grossmann Award in 2009 and the Academy Award of the Berlin-Brandenburg Academy of Science in 2010. In 2013 he was awarded the Herschel Medal of the Royal Astronomical Society in the UK.