Ervand George Kogbetliantz ( hy, Երվանդ Գևորգի Կողբետլյանց; February 22, 1888 in Rostov-on-the-Don – 1974 in Paris, France) was an Armenian-American mathematician and the first president of the

Yerevan State University Yerevan State University (YSU; hy, Երևանի Պետական Համալսարան, ԵՊՀ, ''Yerevani Petakan Hamalsaran''), also simply University of Yerevan, is the oldest continuously operating public university in Armenia. Founded in 1919 ...

. He left Russia in 1918. He received a Doctorate in mathematics from the

University of Paris , image_name = Coat of arms of the University of Paris.svg , image_size = 150px , caption = Coat of Arms , latin_name = Universitas magistrorum et scholarium Parisiensis , motto = ''Hic et ubique terrarum'' (Latin) , mottoeng = Here and a ...

in 1923. His mathematical work was mainly on

infinite series In mathematics, a series is, roughly speaking, a description of the operation of adding infinitely many quantities, one after the other, to a given starting quantity. The study of series is a major part of calculus and its generalization, math ...

, on the theory of

orthogonal polynomials In mathematics, an orthogonal polynomial sequence is a family of polynomials such that any two different polynomials in the sequence are orthogonality, orthogonal to each other under some inner product. The most widely used orthogonal polynomial ...

, on an algorithm for

singular value decomposition In linear algebra, the singular value decomposition (SVD) is a factorization of a real or complex matrix. It generalizes the eigendecomposition of a square normal matrix with an orthonormal eigenbasis to any \ m \times n\ matrix. It is related ...

which bears his name, on algorithms for the evaluation of elementary functions in computers, and on the enumeration of prime elements of the

Gaussian integers In number theory, a Gaussian integer is a complex number whose real and imaginary parts are both integers. The Gaussian integers, with ordinary addition and multiplication of complex numbers, form an integral domain, usually written as \mathbf /ma ...

. He also invented a three-dimensional version of chess, and was working at his death with Bobby Fischer on a game of chess for three people. When he first went to America (1941), he taught Mathematics at

Lehigh University Lehigh University (LU) is a private research university in Bethlehem, Pennsylvania in the Lehigh Valley region of eastern Pennsylvania. The university was established in 1865 by businessman Asa Packer and was originally affiliated with the Epis ...

. In the early 1950s, he was a consultant for IBM in New York City and taught at Columbia University. Prior to moving back to Paris and retiring, he was a professor at

Rockefeller University The Rockefeller University is a private biomedical research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and provides doctoral and postdoctoral education. It is classif ...

Articles and books

* ''Recherches sur la summabilité des séries ultrasphériques par la méthode des moyennes arithmétiques'', J. Math. Pures Appl. 9, 107–187, 1924. * ''Fundamentals of mathematics from an advanced viewpoint'', 4 volumes, Gordon and Breach Science Publishers, 1968. * (with Alice Krikorian) ''Handbook of first complex prime numbers'', Gordon and Breach Science Publishers, 1971.

External links

*
Life magazine, 9 June 1952, on his three-dimensional chess board

Two photos of Kogbetliantz from the Pontigny Conference at Mount Holyoke College in 1944
{{DEFAULTSORT:Kogbetliantz, Ervand G 1888 births 1974 deaths Deaths from cancer in France 20th-century Armenian mathematicians Numerical analysts Singular value decomposition Academic staff of Yerevan State University University of Paris alumni Soviet emigrants to the United States