Kurt Heegner

He is famous for his mathematical discoveries in number theory and, in particular, the Stark–Heegner theorem.

In 1952, he published the Stark–Heegner theorem which he claimed was the solution to a classic number theory problem proposed by the great mathematician Gauss, the class number 1 problem.

Heegner's proof was accepted as essentially correct after a 1967 announcement by Bryan Birch, and definitively resolved by a paper by Harold Stark that had been delayed in publication until 1969 (Stark had independently arrived at a similar proof, but disagrees with the common notion that his proof is "more or less the same" as Heegner's).

[1] Stark attributed Heegner's mistakes to the fact he used a textbook by Weber that contained some results with incomplete proofs.

The book The Legacy of Leonhard Euler: A Tricentennial Tribute by Lokenath Debnath claims on page 64, that Heegner was a "retired Swiss mathematician", but he appears to have been neither Swiss nor retired at the time of his 1952 paper.[2][3][relevant?]