**Øystein Ore** was a Norwegian mathematician who worked in ring theory, Galois theory and graph theory.

- Øystein was born in Kristiania, Norway.
- The city was still named Kristiania when Ore attended the Katedralskole there.
- The city of Kristiania was renamed Oslo in 1925 by which time Ore had returned there as an assistant, but before this he had studied in a number of universities while undertaking research.
- Ore's research was supervised by Thoralf Skolem at Kristiania but he spent time at Göttingen University where he was influenced by Emmy Noether finding her new approach to algebra particularly exciting.
- Before taking up the research assistant position at the University of Oslo in 1925, which we referred to above, he made another visit to Göttingen University as a fellow of the International Education Board, and also visited the Sorbonne in Paris.
- Ore was offered an appointment as an Assistant Professor of Mathematics at Yale and in 1927 he left Olso to take up the position.
- In 1931 Ore was honoured by being named Sterling Professor at Yale, a position he held for 37 years until he retired in 1968.
- Ore's early work was on algebraic number fields where he was interested in the problem of decomposing the ideal generated by a prime integer into prime ideals.
- He then worked on non-commutative ring theory and proved his celebrated embedding theorem for a non-commutative integral domain into a division ring.
- In 1930 the Collected Works of Richard Dedekind were published in three volumes, jointly edited by Ore and Emmy Noether.
- Let us look now at some of the other books which Ore published.
- Many of these are quite simple; others are more in the nature of proposed research problems; these have been marked with an asterisk.
- The second volume will be devoted to more special topics: planar graphs, the four-color conjecture, the theory of flow, games, electrical networks, as well as applications to a number of other fields in which graph theory is a principal tool.
- Before we end this description of Ore's mathematics let us look briefly at a couple of papers he wrote right at the end of his life.
- The paper Systematic computations on amicable numbers was written by Ore in collaboration with J Alanen and J Stemple.
- The paper Diameters in Graphs published by Ore in 1968 looks at diameter critical graphs.
- Ore determines all diameter critical graphs in the paper.
- Ore was a member of the American Mathematical Society for many years, serving on the Council during 1934-36 and being Colloquium lecturer in 1941.
- Like many other cultured Scandinavians, he was fluent in several foreign languages.
- He died unexpectedly the day before he was due to lecture at a mathematical meeting in Oslo.

Born 7 October 1899, Kristiania (now Oslo), Norway. Died 13 August 1968, Oslo, Norway.

View full biography at MacTutor

Origin Norway

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive