Paul A. Catlin

Paul Allen Catlin
Born June 25, 1948
Died April 20, 1995 (aged 46)
Fields Mathematics
Alma mater Ohio State University
Thesis Embedding subgraphs and coloring graphs under extremal degree conditions (1976)
Doctoral advisor G. Neil Robertson
Known for Graph theory
Number theory

Paul Allen Catlin (June 25, 1948 – April 20, 1995) was a mathematician, professor of mathematics and Doctor of Mathematics, known for his valuable contributions to graph theory and number theory. He wrote one of the most cited papers in the series of chromatic numbers and Brooks' theorem, entitled Hajós graph coloring conjecture: variations and counterexamples.[1][2][3]

Career

He held a Doctorate in Mathematics degree from Ohio State University, authored over fifty academic papers in number theory and graph theory. Many of his contributions and collaborations have been published in The Fibonacci Quarterly, in The Journal of Number Theory, in the Journal of Discrete Mathematics, and many other academic publications.[3] He co-authored scholarly papers with Arthur M. Hobbs,[4] Béla Bollobás and Paul Erdős,[5] Hong-Jian Lai, Zheng-Yiao Han, and Yehong Shao,[4] among others. He also published papers with G. Neil Robertson, with whom he also completed his dissertation thesis in 1976.[1][6]

Originally from Bridgeport, Connecticut, he majored in Mathematics with a B.A. degree from Carnegie Mellon University in 1970.[1]

From 1972 to 1973, he was a research and teaching assistant at Ohio State University, where he earned the Master of Science degree in Mathematics.[1]

In 1976, he went to work at Wayne State University, where he concentrated the research on chromatic numbers and Brooks' theorem. As a result, Paul A. Catlin published one of the most cited papers in that series: Hajós graph coloring conjecture: variations and counterexamples.,[1][7] which showed that the conjecture raised by Hugo Hadwiger is further strengthened not only by $k \le 4$ but also by $k \ge 7$,[8] which led to the joint paper written with Paul Erdős and Béla Bollobás entitled Hadwiger's conjecture is true for almost every graph.[5]