Theodore Joseph Rivlin (11 September 1926, Brooklyn – 22 July 2006,

Croton-on-Hudson Croton-on-Hudson is a administrative divisions of New York#Village, village in Westchester County, New York, Westchester County, New York (state), New York, United States. The population was 8,327 at the 2020 United States census over 8,070 at the ...

) was an American mathematician, specializing in

approximation theory In mathematics, approximation theory is concerned with how function (mathematics), functions can best be approximation, approximated with simpler functions, and with quantitative property, quantitatively characterization (mathematics), characteri ...

. He is known for his 1969 book ''An Introduction to the Approximation of Functions'' (Dover reprint, 1981), which became a standard text.

Education and career

Rivlin received in 1948 his bachelor's degree from

Brooklyn College Brooklyn College is a public university in Brooklyn, Brooklyn, New York. It is part of the City University of New York system and enrolls about 15,000 undergraduate and 2,800 graduate students on a 35-acre campus. Being New York City's first publ ...

. After serving in the

United States Army Air Force The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

for eighteen months, he became a graduate student in mathematics at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

, where he received in 1953 his Ph.D. with thesis advisor

Joseph L. Walsh __NOTOC__ Joseph Leonard Walsh (September 21, 1895 – December 6, 1973) was an American mathematician who worked mainly in the field of analysis. The Walsh function and the Walsh–Hadamard code are named after him. The Grace–Walsh–Szegő ...

and thesis ''Overconvergent

Taylor series In mathematics, the Taylor series or Taylor expansion of a function is an infinite sum of terms that are expressed in terms of the function's derivatives at a single point. For most common functions, the function and the sum of its Taylor serie ...

and the zeroes of related polynomials''. Rivlin from 1952 to 1955 taught mathematics at

Johns Hopkins University Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hem ...

and from 1955 to 1956 was a research associate at the Institute for Mathematics Sciences at New York University (later renamed the Courant Institute of Mathematical Sciences). He was from 1956 to 1959 a senior mathematical analyst at the Fairchild Engine and Airplane Corporation in Deer Park on

Long Island Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...

; there he began intensive study of approximation theory and

Chebyshev polynomial The Chebyshev polynomials are two sequences of polynomials related to the cosine and sine functions, notated as T_n(x) and U_n(x). They can be defined in several equivalent ways, one of which starts with trigonometric functions: The Chebyshe ...

s in connection with his work on developing thermodynamic tables. From 1959 until his retirement nearly 35 years later, Rivlin was a research staff member at IBM's Thomas J. Watson Research Center in Yorktown Heights, New York. He was on sabbatical from 1969 to 1970 at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

Computer Science Department A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These pro ...

and from 1976 to 1977 at

Imperial College London Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...

's Mathematics Department. From 1966 to 1976 Rivlin was an adjunct professor of mathematics at the Graduate Center of the

City University of New York The City University of New York ( CUNY; , ) is the Public university, public university system of Education in New York City, New York City. It is the largest urban university system in the United States, comprising 25 campuses: eleven Upper divis ...

, where he lectured on approximation theory. For many years he was an associate editor for the '' Journal of Approximation Theory'' and wrote over 80 research articles on approximation theory and computational mathematics. ''The Annals of Numerical Analysis'' published in 1997 a special issue entitled ''The Heritage of P.L. Chebyshev: A Festschrift in honor of the 70th birthday of T.J. Rivlin''.

Selected publications

Articles

* with Nesmith C. Ankeny: * with

Harold S. Shapiro Harold Seymour Shapiro (2 April 1928 – 5 March 2021) was a professor of mathematics at the Royal Institute of Technology in Stockholm, Sweden, best known for inventing the so-called Shapiro polynomials (also known as Golay–Shapiro polynomia ...

: * with Richard Kelisky: * with Charles A. Micchelli and Shmuel Winograd: * with C. A. Micchelli: * with C. A. Micchelli:

Books

*; * **

References

{{DEFAULTSORT:Rivlin, Theodore J. 1926 births 2006 deaths 20th-century American mathematicians Approximation theorists American mathematical analysts Brooklyn College alumni Harvard University alumni IBM employees