John William Theodore Youngs (usually cited as J. W. T. Youngs, known as Ted Youngs; 21 August 1910

Bilaspur, Chhattisgarh Bilaspur, also known as "The City of Festivals", is a city located in Bilaspur District in the Indian state of Chhattisgarh. Bilaspur is the Administrative headquarters of the Bilaspur District and Bilaspur Division. The Chhattisgarh High ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

– 20 July 1970

Santa Cruz, California Santa Cruz ( Spanish for "Holy Cross") is the county seat and largest city of Santa Cruz County, in Northern California. As of the 2020 census, the city population was 62,956. Situated on the northern edge of Monterey Bay, Santa Cruz is a po ...

) was an American mathematician. Youngs was the son of a missionary. He completed his undergraduate study at Wheaton College and received his PhD from

Ohio State University The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best publ ...

in 1934 under

Tibor Radó Tibor Radó (June 2, 1895 – December 29, 1965) was a Hungarian mathematician who moved to the United States after World War I. Biography Radó was born in Budapest and between 1913 and 1915 attended the Polytechnic Institute, studying civ ...

. He then taught for 18 years at

Indiana University Indiana University (IU) is a system of public universities in the U.S. state of Indiana. Campuses Indiana University has two core campuses, five regional campuses, and two regional centers under the administration of IUPUI. *Indiana Universi ...

, where for eight years he was chair of the mathematics department. From 1964 he was a professor at the

University of California, Santa Cruz The University of California, Santa Cruz (UC Santa Cruz or UCSC) is a public land-grant research university in Santa Cruz, California. It is one of the ten campuses in the University of California system. Located on Monterey Bay, on the edge of ...

, where he developed the mathematics faculty and was chair of the academic senate of the university. Youngs worked in geometric topology, for example, questions on the Frechét-equivalence of topological maps. He is famous for the

Ringel–Youngs theorem In graph theory, the Heawood conjecture or Ringel–Youngs theorem gives a lower bound for the number of colors that are :wikt:necessary, necessary for graph coloring on a surface (topology), surface of a given genus (mathematics), genus. For sur ...

(''i.e.'' Ringel and Youngs's 1968 proof of the Heawood conjecture), which is closely related to the analogue of the

four-color theorem In mathematics, the four color theorem, or the four color map theorem, states that no more than four colors are required to color the regions of any map so that no two adjacent regions have the same color. ''Adjacent'' means that two regions sha ...

for surfaces of higher genus. John Youngs was a consultant for

Sandia National Laboratories Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force Bas ...

, the Rand Corporation and the Institute for Defense Analyses as well as a trustee for ''Carver Research Foundation Institute'' in Tuskegee. In 1946–1947 he was a

Guggenheim Fellow Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the a ...

. At the University of Santa Cruz a mathematics prize for undergraduates in named after him.

Sources

* Obituary in Journal of Combinatorial Theory, vol 13, 1972

References

External links

Obituary from the University of California
{{DEFAULTSORT:Youngs, John William Theodore 1910 births 1970 deaths 20th-century American mathematicians Graph theorists Topologists Ohio State University alumni Indiana University faculty University of California, Santa Cruz faculty People from Bilaspur, Chhattisgarh Wheaton College (Illinois) alumni Sandia National Laboratories people American expatriates in India