Onorato Timothy O'Meara (January 29, 1928 – June 17, 2018) was an American mathematician known for his work innumber theory,linear groups andquadratic forms. He was provost emeritus and professor emeritus of mathematics at theUniversity of Notre Dame.

O'Meara was born inSouth Africa and graduated fromUniversity of Cape Town in 1947. He continued there for amaster's degree, then transferring toPrinceton University where he obtained the Ph.D. inmathematics in 1953. He then taught atUniversity of Otago inNew Zealand for three years. Subsequently he returned to New Jersey and was in theInstitute for Advanced Study. He joinedUniversity of Notre Dame in 1962 and becameProvost. He is known for his booksSymplectic Groups,Introduction to Quadratic Forms, andThe Classical Groups and K-Theory (co-author,Alexander J. Hahn ^[de]).

In 2008, the University of Notre Dame Mathematics Library was rededicated and named in O'Meara's honor.^[1]

O'Meara died on June 17, 2018, aged 90.^[2]

• O'Meara, O. T. (1956). "Witt's theorem and the isometry of lattices".Proc. Amer. Math. Soc.7 (1):9–22.doi:10.2307/2033236.JSTOR 2033236.
• O'Meara, O. T. (1956). "Basis structure of modules".Proc. Amer. Math. Soc.7 (6):965–974.doi:10.2307/2033023.JSTOR 2033023.
• O'Meara, O. T. (1957). "Integral equivalence of quadratic forms in ramified local fields".American Journal of Mathematics.79 (1):157–186.doi:10.2307/2372391.JSTOR 2372391.
• O'Meara, O. T. (1959). "Infinite dimensional quadratic forms over algebraic number fields".Proc. Amer. Math. Soc.10 (1):55–58.doi:10.2307/2032887.JSTOR 2032887.
• "On the finite generation of linear groups over Hasse domains".J. Reine Angew. Math.217 (79):79–108. 1965.doi:10.1515/crll.1965.217.79.
• with Barth Pollak:O'Meara, O. T.; Pollak, Barth (1965). "Generation of local integral orthogonal groups".Mathematische Zeitschrift.87 (3):385–400.doi:10.1007/BF01111720.
• O'Meara, O. T. (1968). "The automorphisms of the orthogonal groups Ω_n(V) over fields".American Journal of Mathematics.90 (4):1260–1306.doi:10.2307/2373300.JSTOR 2373300.
• O'Meara, O. T. (1969). "Group-theoretic characterization of transvections using CDC".Mathematische Zeitschrift.110 (5):385–394.doi:10.1007/BF01110686.
• "The automorphisms of the orthogonal groups and their congruence subgroups over arithmetic domains".J. Reine Angew. Math.1969 (238):169–206. 1969.doi:10.1515/crll.1969.238.169.
• "The construction of indecomposable positive definite quadratic forms".J. Reine Angew. Math.276 (99):99–123. 1975.doi:10.1515/crll.1975.276.99.
• "A general isomorphism for linear groups".Journal of Algebra.44 (1):93–142. January 1977.doi:10.1016/0021-8693(77)90167-3.
• "The Idea of a Catholic University: A Personal Perspective".Marquette Law Review. Winter 1995: Symposium on Religiously Affiliated Law Schools.78 (2):389–396.

• 1963, 2000:Introduction to Quadratic Forms, Classics in Mathematics^[3] Springer,ISBN 3540665641
• 1974:Lectures on Linear Groups, American Mathematical Society,ISBN 0-8218-1672-1
• 1978:Symplectic Groups^[4] American Mathematical Society,ISBN 0821815164
• 1989: (with Alexander Hahn)The Classical Groups and K-Theory^[5] Springer,ISBN 3642057373

• Symplectic group
• Classical groups
• K-theory

• "Realizing Fr. Ted's Vision" by Alexander J. Hahn
• O. Timothy O'Meara at theMathematics Genealogy Project

•   Quotations related toO. Timothy O'Meara at Wikiquote