Mark Krein

Mark Grigorievich Krein (Ukrainian: Марко́ Григо́рович Крейн, Russian: Марк Григо́рьевич Крейн; 3 April 1907 – 17 October 1989) was a Soviet mathematician, one of the major figures of the Soviet school of functional analysis. He is known for works in operator theory (in close connection with concrete problems coming from mathematical physics), the problem of moments, classical analysis and representation theory.

Mark Grigorievich Krein
The memorial plaque of Mark Krein
Born	Mark Grigorievich Krein (1907-04-03)3 April 1907 Kyiv, Russian Empire
Died	17 October 1989(1989-10-17) (aged 82) Odesa, Ukrainian SSR, Soviet Union
Nationality	Soviet Union
Citizenship	Soviet Union
Alma mater	I.I. Mechnikov Odesa National University
Known for	Functional analysis Krein space Krein's condition Krein's extension theorem Krein–Milman theorem Krein–Rutman theorem Krein–Smulian theorem Akhiezer–Krein–Favard constant Markov–Krein theorem Tannaka–Krein duality
Awards	Wolf Prize (1982)
Scientific career
Fields	Operator Theory Mathematical Physics
Institutions	I.I. Mechnikov Odesa National University Odesa Construction Institute
Academic advisors	Nikolai Chebotaryov
Doctoral students	Vadym Adamyan Israel Gohberg David Milman Mark Naimark Mikhail Samuilovich Livsic

He was born in Kyiv, leaving home at age 17 to go to Odesa. He had a difficult academic career, not completing his first degree and constantly being troubled by anti-Semitic discrimination. His supervisor was Nikolai Chebotaryov.

He was awarded the Wolf Prize in Mathematics in 1982 (jointly with Hassler Whitney), but was not allowed to attend the ceremony.

David Milman, Mark Naimark, Israel Gohberg, Vadym Adamyan, Mikhail Livsic and other known mathematicians were his students.

He died in Odesa.

On 14 January 2008, the memorial plaque of Mark Krein was unveiled on the main administration building of I.I. Mechnikov Odesa National University.