Michael Ernest O'Nan (August 9, 1943,

Fort Knox, Kentucky Fort Knox is a United States Army installation in Kentucky, south of Louisville and north of Elizabethtown. It is adjacent to the United States Bullion Depository, which is used to house a large portion of the United States' official gold res ...

– July 31, 2017,

Princeton, New Jersey Princeton is a municipality with a borough form of government in Mercer County, in the U.S. state of New Jersey. It was established on January 1, 2013, through the consolidation of the Borough of Princeton and Princeton Township, both of whi ...

) was an American mathematician, specializing in group theory. O'Nan received his PhD in 1970 from

Princeton University Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

under

Daniel Gorenstein Daniel E. Gorenstein (January 1, 1923 – August 26, 1992) was an American mathematician. He earned his undergraduate and graduate degrees at Harvard University, where he earned his Ph.D. in 1950 under Oscar Zariski, introducing in his dissertati ...

with thesis ''A Characterization of the Three-Dimensional Projective Unitary Group over a Finite Field''. He was a professor at

Rutgers University Rutgers University (; RU), officially Rutgers, The State University of New Jersey, is a Public university, public land-grant research university consisting of four campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's ...

. In 1976 he found strong evidence for the existence of a sporadic group, which

Charles Sims Charles Sims may refer to: * Charles Sims (painter) (1873–1928), British painter * Charles Sims (mathematician) (1938–2017), American mathematician * Charles Sims (aviator) (1899–1929), British World War I flying ace * Charles Sims (America ...

constructed. The group is now named the O'Nan group after O'Nan. The O'Nan–Scott theorem in group theory is also named after O'Nan, who discovered it independently from Leonard Scott. It describes the

maximal subgroup In mathematics, the term maximal subgroup is used to mean slightly different things in different areas of algebra. In group theory, a maximal subgroup ''H'' of a group ''G'' is a proper subgroup, such that no proper subgroup ''K'' contains ''H'' s ...

s of the symmetric groups.

Selected works

* ''Linear Algebra'' (= ''Eagle Mathematics Series.'' vol. 2A). Harcourt Brace Jovanovich, New York NY, 1971, (2nd edition.1976, ; 3rd edition. with Herbert Enderton. Harcourt Brace Jovanovich, San Diego CA, 1990, ). * *

References

1943 births 20th-century American mathematicians Group theorists Princeton University alumni Rutgers University faculty 2017 deaths 21st-century American mathematicians {{US-mathematician-stub