| Gary Chartrand | |
| Birth Date: | 24 August 1936 |
| Thesis Title: | Graphs and Their Associated Line-Graphs |
| Alma Mater: | Michigan State University |
| Nationality: | American |
| Doctoral Advisor: | Edward Nordhaus |
| Doctoral Students: | Ortrud Oellermann |
Gary Theodore Chartrand (born 1936) is an American-born mathematician who specializes in graph theory. He is known for his textbooks on introductory graph theory and for the concept of ahighly irregular graph.
Gary Chartrand was born in 1936. He was raised in Sault Ste. Marie, Michigan and attended J. W. Sexton High School located in Lansing, Michigan. As an undergraduate student, he initially majored in chemical engineering, but switched to mathematics in his junior year, in which he also became a member of the honorary mathematics society Pi Mu Epsilon.
He earned his B. S. from Michigan State University, where he majored in mathematics and minored in physical sciences and foreign languages. Michigan State University also awarded him a Master of Science and a PhD for his work in graph theory in 1964. Chartrand became the first doctoral student of Edward Nordhaus, and the first doctoral student at Michigan State University to research graph theory. His dissertation was Graphs and Their Associated Line-Graphs. Chartrand worked with Frank Harary at the University of Michigan, where he spent a year as a Research Associate, and the two have published numerous papers together (along with other authors).
The topic of highly irregular graphs was introduced by Chartrand, Paul Erdős and Ortrud Oellermann.[1]
Other contributions that Chartrand has made involve dominating sets, distance in graphs, and graph coloring. During his career at Western Michigan University, he advised 22 doctoral students in their research on aspects of graph theory. Chartrand is currently a professor emeritus of mathematics at Western Michigan University.