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Volodymyr Petryshyn

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22 Jan 1929

Liashky Murovani, Lvov, Galicia (now Ukraine)

Prezentare
Volodymyr Petryshyn was 10 years old when World War II broke out and his education was severely disrupted, becoming a displaced person at the end of the war. In 1950 he emigrated from Germany to the United States and completed his education there. In 1961 he was awarded his doctorate from Columbia University.

From 1964 Petryshyn taught at the University of Chicago, then in 1967 he was appointed to Rutgers University. He was elected to the Shevchenko Scientific Society in 1980 and to the Academy of Sciences of the Ukraine in 1992. He is also an honorary member of the Kiev Mathematical Society, being elected in 1989.

Petryshyn's main work in has been in iterative and projective methods, fixed point theorems, nonlinear Friedrichs extension, approximation-proper mapping theorem, and topological degree and index theories for multivalued condensing maps. His mathematical achievements are described by Andrushkov in :

Petryshyn's main achievements are in functional analysis . His major results include the development of the theory of iterative and projective methods for the constructive solution of linear and nonlinear abstract and differential equations .

The theory of A-proper maps was developed by Petryshyn and this work is described in :

Petryshyn is a founder and principal developer of the theory of approximation-proper (A-proper) maps, a new class of maps which attracted considerable attention in the mathematical community. He has shown that the theory of A-proper type maps not only extends and unifies the classical theory of compact maps with some recent theories of condensing and monotone-accretive maps, but also provides a new approach to the constructive solution of nonlinear abstract and differential equations. ... The theory has been applied to ordinary and partial differential equations .

Source:School of Mathematics and Statistics University of St Andrews, Scotland