Friedhelm Waldhausen


Friedhelm Waldhausen is a German mathematician known for his work in algebraic topology. He made fundamental contributions in the fields of 3-manifolds and K-theory.

Career

Waldhausen studied mathematics at the universities of Göttingen, Munich and Bonn. He obtained his Ph.D. in 1966 from the University of Bonn; his advisor was Friedrich Hirzebruch and his thesis was entitled "Eine Klasse von 3-dimensionalen Mannigfaltigkeiten".
After visits to Princeton University, the University of Illinois and the University of Michigan he moved in 1968 to the University of Kiel, where he completed his habilitation.
In 1969, he was appointed professor at the Ruhr University Bochum before in 1971 becoming a professor at Bielefeld University, an appointment he held until his retirement in 2004.

Academic work

His early work was mainly on the theory of 3-manifolds. He dealt mainly with Haken manifolds and Heegaard splitting. Among other things, he proved that, roughly speaking, any homotopy equivalence of Haken manifolds is homotopic to a homeomorphism, i.e. that closed Haken manifolds are topologically rigid. He put forward the Waldhausen conjecture about Heegaard splitting.
In the mid-seventies, he extended the connection between geometric topology and algebraic K-theory by introducing A-theory, a kind of algebraic K-theory for topological spaces. This led to new foundations for algebraic K-theory and also gave new impetus to the study of highly structured ring spectra.

Recognition

Today, Waldhausen is seen, together with Daniel Quillen, as one of the pioneers of algebraic K-theory. Among others, he was awarded the von Staudt Prize in 2004 along with Günter Harder, and an honorary doctorate from the Universität Osnabrück.

Important publications

Algebraic -theory of spaces, Algebraic and
geometric topology, 318--419, Lecture Notes
in Math., 1126, Springer, Berlin, 1985.
Algebraic -theory of spaces, concordance,
and stable homotopy theory, Algebraic topology and algebraic -theory
, 392--417, Ann. of Math. Stud., 113, Princeton
Univ. Press, Princeton, NJ, 1987.
The map,
Algebraic topology and algebraic -theory,
418--431, Ann. of Math. Stud., 113, Princeton Univ. Press, Princeton,
NJ, 1987.