Wolfgang Haken

Haken died in Champaign, Illinois on October 2, 2022, aged 94.

In 1978, Haken delivered an invited address at the International Congress of Mathematicians in Helsinki. He was a recipient of the 1979 Fulkerson Prize of the American Mathematical Society for his solution with Appel of the four-color theorem.

In 1976, together with colleague Kenneth Appel at the University of Illinois at Urbana-Champaign, Haken solved the four-color theorem. They proved that any two-dimensional map, with certain limitations, can be filled in with four colors without any adjacent “countries” sharing the same color. Haken has introduced several ideas, including Haken manifolds, Kneser-Haken finiteness, and an expansion of the work of Kneser into a theory of normal surfaces. Much of his work has an algorithmic aspect, and he is a figure in algorithmic topology. One of his key contributions to this field is an algorithm to detect if a knot is unknotted.

Wolfgang Haken (June 21, 1928 – October 2, 2022) was a German American mathematician who specialized in topology, in particular 3-manifolds.

Haken was born on June 21, 1928 in Berlin, Germany. His father was Werner Haken, a physicist who had Max Planck as a doctoral thesis advisor. In 1953, Haken earned a Ph.D. degree in mathematics from Christian-Albrechts-Universität zu Kiel (Kiel University) and married Anna-Irmgard von Bredow, who earned a Ph.D. degree in mathematics from the same university in 1959. In 1962, they left Germany so he could accept a position as visiting professor at the University of Illinois at Urbana-Champaign. He became a full professor in 1965, retiring in 1998.