Harald Bohr | |
---|---|

Harald Bohr | |

Born | Harald August Bohr 22 April 1887 ^{[1]}Copenhagen ^{[1]} |

Died | 22 January 1951 | (aged 63)

Resting place | Assistens Cemetery, Copenhagen |

Nationality | Danish |

Alma mater | University of Copenhagen |

Occupation | Mathematician |

Parent(s) | Christian and Ellen Bohr^{[1]} |

Relatives | Niels Bohr (brother) |

Olympic medal record | ||
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Representing Denmark | ||

Men's football | ||

1908 London | Team Competition |

**Harald August Bohr** (22 April 1887 – 22 January 1951) was a Danish mathematician and footballer. After receiving his doctorate in 1910, Bohr became an eminent mathematician, founding the field of almost periodic functions. His brother was the Nobel Prize-winning physicist Niels Bohr. He was a member of the Danish national football team for the 1908 Summer Olympics, where he won a silver medal.

## Biography

Bohr was born in 1887 to Christian Bohr, a professor of physiology, from a Lutheran background, and Ellen Adler Bohr, a woman from a wealthy Jewish family of local renown.^{[2]} Harald had a close relationship with his elder brother, which *The Times* likened to that between Captain Cuttle and Captain Bunsby in Charles Dickens' *Dombey and Son*.^{[3]}

## Mathematical career

Like his father and brother before him, in 1904 Bohr enrolled at the University of Copenhagen, where he studied mathematics, obtaining his masters in 1909 and his doctorate a year later. Among his tutors were Hieronymus Georg Zeuthen and Thorvald N. Thiele.^{[4]} Bohr worked in mathematical analysis; much of his early work was devoted to Dirichlet series including his doctorate, which was entitled *Bidrag til de Dirichletske Rækkers Theori* (*Contributions to the Theory of Dirichlet Series*).^{[5]} A collaboration with Göttingen-based Edmund Landau resulted in the Bohr–Landau theorem, regarding the distribution of zeroes in zeta functions.^{[2]}

Bohr worked in mathematical analysis, founding the field of almost periodic functions, and worked with the Cambridge mathematician G. H. Hardy.

In 1915 he became a professor at Polyteknisk Læreanstalt (today Technical University of Denmark), working there until 1930, when he took a professorship at the University of Copenhagen. He remained in this post for 21 years until his death in 1951. Børge Jessen was one of his students there.

He was a visiting professor at Stanford University during the academic year 1930–1931.^{[6]} He was a visiting scholar at the Institute for Advanced Study in the summer of 1948.^{[7]}

In the 1930s Bohr was a leading critic of the anti-Semitic policies taking root in the German mathematical establishment, publishing an article criticising Ludwig Bieberbach's ideas in *Berlingske Aften* in 1934.^{[8]}

## Football

Bohr was also an excellent football player. He had a long playing career with Akademisk Boldklub, making his debut as a 16-year-old in 1903.^{[9]} During the 1905 season he played alongside his brother Niels, who was a goalkeeper. Harald was selected to play for the Danish national football team in the 1908 Summer Olympics, where football was an official event for the first time. Though a Danish side had played at the 1906 Intercalated Games, the opening match of the 1908 Olympic tournament was Denmark's first official international football match. Bohr scored two goals as Denmark beat the French "B" team 9–0.^{[10]} In the next match, the semi-final, Bohr played in a 17–1 win against France, which remains an Olympic record.^{[11]} Denmark faced hosts Great Britain in the final, but lost 2–0, and Bohr won a silver medal.^{[2]}^{[5]} After the Olympics he made one further appearance for the national team, in a 2–1 victory against an England amateur team in 1910.^{[12]} His popularity as a footballer was such that when he defended his doctoral thesis the audience was reported as having more football fans than mathematicians.^{[13]}

## Teacher

Bohr was known as an extremely capable academic teacher and the annual award for outstanding teaching at the University of Copenhagen is called the Harald, in honour of Harald Bohr. With Johannes Mollerup, Bohr wrote an influential four-volume textbook *Lærebog i Matematisk Analyse* (*Textbook in mathematical analysis*).^{[14]}

## Kaj Munk

Following the murder of Kaj Munk on 4 January 1944 the Danish resistance newspaper *De frie Danske* brought condemning reactions from influential Scandinavians, including Bohr.^{[15]}

## See also

- Bohr–Mollerup theorem
- Bohr compactification
- Bohr–Favard inequality
- Danish Mathematical Society
- List of select Jewish football (association; soccer) players

## References

- ^
^{a}^{b}^{c}*Politiets Registerblade*[*Register cards of the Police*] (in Danish). Copenhagen: Københavns Stadsarkiv. 7 June 1892. Station Dødeblade (indeholder afdøde i perioden). Filmrulle 0002. Registerblad 3341. ID 3308989. - ^
^{a}^{b}^{c}J J O'Connor and E F Robertson. "Harald August Bohr". Retrieved 17 August 2008. **^**"Obituary: Prof. Harald Bohr".*The Times*. 6 February 1951. p. 8 – via Times Digital Archive 1785–1985.**^**Bochner, Salomon (January 1952). "Harald Bohr".*Bulletin of the American Mathematical Society*.**58**(1): 72–75. doi:10.1090/S0002-9904-1952-09551-3. Retrieved 21 December 2008.- ^
^{a}^{b}H. P. Boas (1997). "The Football Player and the Infinite Series". arXiv:math.CV/9705204. **^**Putnam, T. M. (1931). "The November meeting in Los Angeles".*Bull. Amer. Math. Soc*.**37**: 3–5. doi:10.1090/S0002-9904-1931-05068-0.**^**"Scholars".*Institute for Advanced Study*.**^**Menzler-Trott, Eckart (2008).*Logic's Lost Genius: The Life of Gerhard Gentzen*. AMS. p. 115. ISBN 0-8218-3550-5.**^**Akademisk Boldklub. "AB's historie". Archived from the original on 10 December 2008. Retrieved 18 August 2008.**^**"Harald Bohr". Sports-Reference.com. Archived from the original on 18 April 2020. Retrieved 18 August 2008.**^**"Facts and figures – Team achievements / records". Beijing Olympics 2008 official website. Archived from the original on 5 September 2008. Retrieved 18 August 2008.**^**"Denmark – Internationals 1908–1912". RSSSF. Retrieved 18 August 2008.**^**"Mathematical Moments – Harald Bohr". Plus magazine. Retrieved 20 August 2008.**^**"Bibliography of Harald Bohr". University of Copenhagen. Archived from the original on 28 July 2009. Retrieved 20 August 2008.**^**"KAJ MUNK IN MEMORIAM".*De frie Danske*(in Danish). January 1944. p. 6. Retrieved 18 November 2014.Meddelelsen om denne nye Voldsdaad i Danmark, Mordet paa en af vore største Digtere og modigste Personligheder, har opfyldt os alle med Afsky og Forfærdelse, og vi forstaar, at Kaj Munks Anseelse og den Beundring man nærede for ham her i Sverige, var saa stor, at vore Følelser deles af det svenske Folk

## External links

- O'Connor, John J.; Robertson, Edmund F., "Harald Bohr",
*MacTutor History of Mathematics archive*, University of St Andrews. - Danish national team profile
- Some photos of Harald Bohr
- Media related to Harald Bohr (mathematician) at Wikimedia Commons