A note on pronunciation: my surname rhymes with "feast" and "least". It does not rhyme with "Christ" and it does not rhyme with "Trieste".

Date of birth: 29.Dec 1970. I grew up in Darmstadt (Germany), and I studied for 3 years at the Universität Bayreuth.

I did my MSc and PhD at Warwick University in England, under the supervision of Colin Rourke

I worked as a postdoc for 2 years at the CMI Marseille (France) with Hamish Short, financed by a grant from the European Community.

Then I worked for another 2 years at the Pacific institute for the mathematical sciences at UBC in Vancouver (Canada), where my research advisor was Dale Rolfsen.

Since September 2001 I work in Rennes.

Since December 2019 I am a naturalized French citizen.

I am married to Aline Roumy. We have two little boys, born in 2009 and 2013.

I am an amateur musician. I play the viola. (Note that it is unfortunately not me who is playing in this video.)

Photo taken on Mount Tamalpais, with a view over the San Francisco bay. This picture was taken in 2007, when I spent a semester at MSRI.