Theodore Joseph Rivlin (11 September 1926, Brooklyn – 22 July 2006, Croton-on-Hudson) was an American mathematician, specializing in approximation theory.
After serving in the United States Army Air Force for eighteen months, he became a graduate student in mathematics at Harvard University, where he received in 1953 his Ph.D. with thesis advisor Joseph L. Walsh and thesis Overconvergent Taylor series and the zeroes of related polynomials.
He was from 1956 to 1959 a senior mathematical analyst at the Fairchild Engine and Airplane Corporation in Deer Park on Long Island; there he began intensive study of approximation theory and Chebyshev polynomials in connection with his work on developing thermodynamic tables.
[1] From 1966 to 1976 Rivlin was an adjunct professor of mathematics at the Graduate Center of the City University of New York, where he lectured on approximation theory.
[1] The Annals of Numerical Analysis published in 1997 a special issue entitled The Heritage of P.L.