Gerhard Ringel
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Gerhard Ringel (born 1920, Prague) 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.
[edit] References
- Ringel, Gerhard; Youngs, J.W.T. (1968). "Solution of the Heawood map-coloring problem". Proc. Nat. Acad. Sci. USA 60: 438–445. DOI:10.1073/pnas.60.2.438. MR0228378.
- Hartsfield, Nora; Ringel, Gerhard (1990). Pearls in graph theory. Academic Press, Boston, MA. ISBN 0-12-328552-6.
[edit] External links
- Retired mathematics professor Gerhard Ringel gives his world-class butterfly collection to UCSC, UC Santa Cruz Review, Fall 2006