# Harald Bohr

Harald August Bohr ( born April 22, 1887 in Copenhagen, † January 22, 1951 in Gentofte ) was a Danish mathematician and footballer.

## Life and work

Harald Bohr was the son of the Danish physiologist Christian Bohr, his brother was the physicist Niels Bohr. Bohr's research areas were in the range of function theory and analytic number theory.

He studied from 1904 at the University of Copenhagen mathematics. First drilling pursued but also a career as an athlete. He was, in addition to his skills as a scientist, as one of the best footballers of his time, was a player of the Danish national team and won at the Olympic Summer Games in 1908, the silver medal.

In 1910 he received his doctorate in Copenhagen ( with Edmund Landau, Contributions to the theory of Dirichlet series) and was a few months in Göttingen at Landau.

One focus of his mathematical works were Dirichlet series. In particular, he examined, partly with Edmund Landau, the Riemann ζ - function, probably the best known and most important Dirichlet series. To put it simply - - stating that the vast number of zeros of the Riemann ζ - function in an arbitrarily small strip around the critical line is both the set of Bohr -Landau, who in 1914 formulated. In addition, drilling is the founder of the theory of almost periodic functions in a series of papers from 1924 to 1926 in the Acta Mathematica. In theory, the gamma function, he is one of the namesake for the set of Bohr - Mollerup. Also in 1914 proved he set that follows for that for today set of Bohr ( via power series ) is called. The constant is possible.

In 1915 Bohr professor at the Polytechnic College in Copenhagen, 1930, he was appointed to the University of Copenhagen. From 1926 to 1951, interrupted only from 1930 to 1936, he was president of the Danish Mathematical Society (DMF).

In 1932 he gave a plenary lecture at the International Congress of Mathematicians in Zurich ( Almost Periodic Functions of a complex variable ) and 1950 he was Invited Speaker on the ICM in Cambridge (Massachusetts ) (A survey of the different proofs of the main theorems in the theory of almost periodic functions ).

1934 saw an open letter by Ludwig Bieberbach to drilling in the annual report of the German Mathematical Society (DMV ) for a scandal that Bieberbach's resignation from his position in the DMV had the consequence. Bieberbach had this letter, in which he ( had Jewish ancestors ) to a critique of Bohr went down to his mathematician typing, published without a vote in the annual report.

## Writings

- Bohr " Almost Periodic Functions", Annual Report DMV, Bd.34, 1926.
- Bohr " The Riemann zeta function ," Annual Report DMV Bd.24, 1915.
- Bohr "On the uniform convergence of Dirichlet series ", Journal of Pure and Applied Mathematics, Vol 143, 1913.
- Bohr, Harald Cramér Recent studies on analytic number theory, Encyclopedia of Mathematical Sciences, 1922.