Born in
Meddewade, Jannsen studied mathematics and physics at the
University of Hamburg with
Diplom in mathematics in 1978 and with
Promotion (PhD) in 1980 under Helmut Brückner and
Jürgen Neukirch with thesis
Über Galoisgruppen lokaler Körper (On Galois groups of local fields). In the academic year 1983–1984 he was a postdoc at
Harvard University. From 1980 to 1989 he was an assistant and then
docent at the
University of Regensburg, where he received in 1988 his
habilitation. From 1989 to 1991 he held a research professorship at the
Max-Planck-Institut für Mathematik in
Bonn. In 1991 he became a full professor at the
University of Cologne and since 1999 he has been a professor at the University of Regensburg. Jannsen's research deals with, among other topics, the
Galois theory of
algebraic number fields, the theory of
motives in algebraic geometry, the Hasse principle (local–global principle), and resolution of singularities. In particular, he has done research on a
cohomology theory for
algebraic varieties, involving their extension in mixed motives as a development of research by
Pierre Deligne, and a
motivic cohomology as a development of research by
Vladimir Voevodsky. In the 1980s with Kay Wingberg he completely described the absolute Galois group of
p-adic number fields,
i.e. in the local case. In 1994 he was an Invited Speaker with talk
Mixed motives, motivic cohomology and Ext-groups at the
International Congress of Mathematicians in
Zürich. He was elected in 2009 a full member of the
Bayerische Akademie der Wissenschaften and in 2011 a full member of the
Academia Europaea. His doctoral students include Moritz Kerz. == Selected publications ==