Gerhard Ringel

Gerhard Ringel (born October 28, 1919, Kolnbrunn, Austria. Died June 24, 2008, Santa Cruz, California) is a German mathematician who earned his Ph.D. from the University of Bonn in 1951. He is one of the pioneers in graph theory and contributed significantly to the proof of the Heawood conjecture (now Ringel-Youngs theorem).

Gerhard Ringel spent much of his career at the University of California, Santa Cruz, where he also spent time surfing and collecting butterflies.

References

*cite journal
last= Ringel
first= Gerhard
coauthors= Youngs, J.W.T.
title = Solution of the Heawood map-coloring problem
journal = Proc. Nat. Acad. Sci. USA
volume = 60
pages = 438–445
year = 1968
doi = 10.1073/pnas.60.2.438
id = MathSciNet | id = 0228378
*cite book
last= Hartsfield
first= Nora
coauthors= Ringel, Gerhard
title=Pearls in graph theory
publisher= Academic Press, Boston, MA
year= 1990
id= ISBN 0-12-328552-6

External links

*MathGenealogy |id=11109

* [http://review.ucsc.edu/fall06/RevF06-pp14-15_Flights.pdf Retired mathematics professor Gerhard Ringel gives his world-class butterfly collection to UCSC] , UC Santa Cruz Review, Fall 2006