It is with sadness that I inform you of the death of Professor Gerhard Ringel. Gerhard came to UCSC as Professor in 1970. He was one of the world leaders in the fields of Combinatorics and Graph Theory and was much honored for his seminal work including the solution (with J.W.T. Youngs) of the famous Heawood Conjecture in genus p greater than one. This conjecture gave a formula for the minimum number of colors H(p) needed to color a map on a surface of genus p, namely
H(p) = [ 1/2( 7 + √( 48p + 1)) ]
The only exceptions in their proof were the Sphere , Plane and Klein Bottle.
He was awarded two honorary degrees, one from Karlsruhe and the other from Berlin, and served on several distinguished editorial boards. In 1988, he was honored by the Santa Cruz Division of the Academic Senate by his selection as Faculty Research Lecturer.
Gerhard served as our Chair for thirteen years and was admired and liked by his colleagues. A memorial service is being planned for the Fall.
Editor's note: The Fall 2006 issue of UC Santa Cruz Review magazine featured an article about Ringel's butterfly collection, which he donated to the UCSC Museum of Natural History Collections.