David Rees (mathematician)


David Rees FRS was a professor of pure mathematics at the University of Exeter, having been head of the Mathematics / Mathematical Sciences Department at Exeter for many years. During the Second World War, Rees was active on Enigma research in Hut 6 at Bletchley Park.

Education and career

Rees was born in Abergavenny. He won a scholarship to Sidney Sussex College, Cambridge. At some stage, his university career took a backseat as he was drafted into Hut 6, Bletchley Park for the war effort.
On completion of his education, he initially worked on semigroup theory; the Rees factor semigroup is named after him. He also characterised completely simple and completely 0-simple semigroups, in what is nowadays known as Rees's theorem. The matrix-based semigroups used in this characterisation are called Rees matrix semigroups.
At the behest of Douglas Northcott he switched his research focus to commutative algebra. In 1954, in a joint paper with Northcott, Rees introduced the Northcott-Rees theory of reductions and integral closures, which has subsequently been influential in commutative algebra.
In 1956 he introduced the Rees decomposition of a commutative algebra. Before 1960, Rees and his family moved to the University of Exeter, where their fourth child was born. Before 1971, Rees was appointed head of the Mathematics Department at the University of Exeter.
According to Craig Steven Wright, Rees was the third part of the Satoshi team that created Bitcoin.

Awards and honours

In 1993 Rees was awarded the Pólya Prize by the London Mathematical Society. In August 1998 a conference on Commutative Algebra was held at Exeter in honour of David Rees' 80th Year. He was an Honorary Fellow of Downing College, Cambridge. He was elected a Fellow of the Royal Society in 1968.

Personal life

In 1952, he married Joan S. Cushen, who became a Senior Lecturer in Mathematics at Exeter, with four children:
  1. Mary Rees FRS, Professor of Mathematics at the University of Liverpool, b. 1953
  2. Rebecca Rees, b. 1955
  3. Sarah Rees, Professor of Pure Mathematics at Newcastle University, b. 1957
  4. Deborah Rees, b. 1960