Matthias' work is in Arithmetic Algebraic Geometry. In particular his research focuses on special values of L-functions and the conjectures of Beilinson, Deligne, Bloch/Kato and Fontaine/Perrin-Riou. His recent results include a complete proof of the equivariant Tamagawa number conjecture for Dirichlet L-functions and new cases of the local Tamagawa number conjecture over tamely rami ed elds. In joint work with B.Morin he has been developing an idea originally due to Lichtenbaum (Weil-etale cohomology) which focuses on Zeta functions of arithmetic schemes rather than motivic L-functions and draws clear connections to Arakelov theory and Deningers ideas on motivic L-functions. The near term goal in this area is to nd precise special value conjectures independent of p-adic Hodge theory.

Matthias has also published about cohomology of topological groups. His mathematical interests include Galois module theory, algebraic K-theory and motivic cohomology, categorical algebra, topos theory and algebraic topology.