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{{Short description|Norwegian mathematician}}{{Infobox scientist
'''Viggo Brun''' (13 October 1885, [[Lier, Norway|Lier]] – 15 August 1978, [[Drøbak]]) was a [[Norway|Norwegian]] [[mathematics|mathematician]].
| name = Viggo Brun
| image = Viggo Brun 1927-05-25.jpg
| birth_date = 13 October 1885
| birth_place = Lier, Norway
| death_date = {{d-da|15 August 1978|13 October 1885}}
| death_place = Drøbak, Norway
| citizenship = Norway
| fields = Number Theory
| known_for = Brun's Theorem, Brun Sieve
}}


'''Viggo Brun''' (13 October 1885 – 15 August 1978) was a [[Norway|Norwegian]] professor, [[mathematician]] and [[Number theory|number theorist]].
He studied at the [[University of Oslo]] and began research at the [[University of Göttingen]] in 1910. In 1923, Brun became a professor at the [[Norwegian Institute of Technology|Technical University]] in Trondheim and in 1946 a professor at the [[University of Oslo]]. He retired in 1955 at the age of 70.
<ref>{{cite web|url= http://www.numbertheory.org/obituaries/OTHERS/brun/brun.html|title= Viggo Brun|publisher =numbertheory.org |date= 18 June 2003
|access-date= January 1, 2017 }}</ref>


==Contributions==
In 1915, he introduced a new method, based on [[Adrien-Marie Legendre|Legendre]]'s version of the [[sieve of Eratosthenes]], now known as the ''[[Brun sieve]]'', which addresses additive problems such as [[Goldbach's conjecture]] and the [[Twin prime|twin prime conjecture]]. He used it to prove that there exist infinitely many integers n such that n and n+2 have at most nine prime factors; and that all large even integers are the sum of two 9 (or smaller)-almost primes.
In 1915, he introduced a new method, based on [[Adrien-Marie Legendre|Legendre]]'s version of the [[sieve of Eratosthenes]], now known as the ''[[Brun sieve]]'', which addresses additive problems such as [[Goldbach's conjecture]] and the [[Twin prime|twin prime conjecture]]. He used it to prove that there exist infinitely many integers ''n'' such that ''n'' and ''n''+2 have at most nine [[prime factor]]s, and that all large even integers are the sum of two numbers with at most nine prime factors.<ref>{{cite web |author1=J J O'Connor |author2=E F Robertson |title=Viggo Brun |url=http://www-groups.dcs.st-and.ac.uk/history/Biographies/Brun.html |archive-url=https://web.archive.org/web/20170116172225/http://www-groups.dcs.st-and.ac.uk/history/Biographies/Brun.html |archive-date=2017-01-16 |access-date=January 1, 2017 |publisher=School of Mathematics and Statistics, University of St Andrews, Scotland}}</ref>


He also showed that the sum of the reciprocals of [[twin prime]]s converges to a finite value, now called [[Brun's constant]]: by contrast, [[Proof that the sum of the reciprocals of the primes diverges|the sum of the reciprocals of all primes is divergent]].
He also showed that the sum of the reciprocals of [[twin prime]]s converges to a finite value, now called [[Brun's constant]]: by contrast, [[Proof that the sum of the reciprocals of the primes diverges|the sum of the reciprocals of all primes is divergent]]. He developed a multi-dimensional [[continued fraction]] algorithm in 1919–1920 and applied this to problems in [[musical theory]]. He also served as [[praeses]] of the [[Royal Norwegian Society of Sciences and Letters]] in 1946.<ref name="tby">{{cite encyclopedia|year=1996|title=Vitenskapsselskapet|encyclopedia=Trondheim byleksikon|author=Bratberg, Terje|editor=Arntzen, Jon Gunnar|publisher=Kunnskapsforlaget|location=Oslo|pages=599–600|isbn=82-573-0642-8}}</ref>
He developed a multi-dimensional [[continued fraction]] algorithm in 1919/20 and applied this to problems in [[musical theory]].


==Biography==
He also served as praeses of the [[Royal Norwegian Society of Sciences and Letters]] in 1946.<ref name=tby>{{cite encyclopedia|year=1996|title=Vitenskapsselskapet|encyclopedia=Trondheim byleksikon|edition=|author=Bratberg, Terje|editor=Arntzen, Jon Gunnar|publisher=Kunnskapsforlaget|location=Oslo|pages=599–600|isbn=82-573-0642-8}}</ref>
Brun was born at Lier in [[Buskerud]], Norway. He studied at the [[University of Oslo]] and began research at the [[University of Göttingen]] in 1910. In 1923, Brun became a professor at the [[File:ViggoBrun.jpg|thumb|Viggo Brun (published in 1911)]] [[Norwegian Institute of Technology|Technical University]] in Trondheim and in 1946 a professor at the [[University of Oslo]].<ref>{{cite web|url= https://snl.no/Viggo_Brun|title= Viggo Brun|publisher = Store norske leksikon|access-date= January 1, 2017 }}</ref>

He retired in 1955 at the age of 70 and died in 1978 (at 92 years-old) at [[Drøbak]] in [[Akershus]], Norway.<ref>{{cite web|url= https://nbl.snl.no/Viggo_Brun
|title= Viggo Brun|publisher = Norsk biografisk leksikon |author= Bent Birkeland|access-date= January 1, 2017 }}</ref>


==See also==
==See also==
Line 15: Line 31:
* [[Brun sieve]]
* [[Brun sieve]]
* [[Sieve theory]]
* [[Sieve theory]]


== Fotnoter ==
{{notelist}}



==References==
==References==
{{Reflist}}
{{Reflist}}
* [[Heini Halberstam|H. Halberstam]] and [[H. E. Richert]], ''Sieve methods'', Academic Press (1974) ISBN 0-12-318250-6. ''Gives an account of Brun's sieve''.
* C.J. Scriba, ''Viggo Brun'', Historia Mathematica '''7''' (1980) 1-6.
* [http://www.numbertheory.org/obituaries/OTHERS/brun/ C.J. Scriba, ''Zur errinerung an Viggo Brun'', Mitt. Math. Ges. Hamburg '''11''' (1985) 271-290]


==External links==
==Other sources==
* [[Heini Halberstam|H. Halberstam]] and [[H. E. Richert]], ''Sieve methods'', Academic Press (1974) {{ISBN|0-12-318250-6}}. ''Gives an account of Brun's sieve''.
* Brun's Constant: http://planetmath.org/encyclopedia/BrunsConstant.html
* C.J. Scriba, ''Viggo Brun'', Historia Mathematica '''7''' (1980) 1–6.
* Brun's Pure Sieve: http://planetmath.org/encyclopedia/BrunsPureSieve.html
* [http://www.numbertheory.org/obituaries/OTHERS/brun/ C.J. Scriba, ''Zur Erinnerung an Viggo Brun'', Mitt. Math. Ges. Hamburg '''11''' (1985) 271-290]


==External links==
*[https://web.archive.org/web/20030304091118/http://planetmath.org/encyclopedia/BrunsConstant.html Brun's Constant]
*[https://web.archive.org/web/20040604064319/http://planetmath.org/encyclopedia/BrunsPureSieve.html Brun's Pure Sieve]
* [http://arkivportalen.no/side/arkiv/detaljer?arkivId=no-NTNU_arkiv000000061437 Viggo Brun personal archive] exists at NTN University Library [https://www.ntnu.no/ub/bibliotek/dora Dorabiblioteket]
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{{Authority control}}
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{{Persondata <!-- Metadata: see [[Wikipedia:Persondata]]. -->
| NAME = Brun, Viggo
| ALTERNATIVE NAMES =
| SHORT DESCRIPTION = Norwegian mathematician
| DATE OF BIRTH = 13 October 1885
| PLACE OF BIRTH =
| DATE OF DEATH = 15 August 1978
| PLACE OF DEATH =
}}
{{DEFAULTSORT:Brun, Viggo}}
{{DEFAULTSORT:Brun, Viggo}}
[[Category:1885 births]]
[[Category:1885 births]]
[[Category:1978 deaths]]
[[Category:1978 deaths]]
[[Category:People from Lier, Norway]]
[[Category:Norwegian mathematicians]]
[[Category:Norwegian mathematicians]]
[[Category:20th-century mathematicians]]
[[Category:20th-century Norwegian mathematicians]]
[[Category:Number theorists]]
[[Category:Number theorists]]
[[Category:Norwegian Institute of Technology faculty]]
[[Category:University of Oslo faculty]]
[[Category:University of Oslo alumni]]
[[Category:University of Oslo alumni]]
[[Category:Academic staff of the Norwegian Institute of Technology]]
[[Category:Academic staff of the University of Oslo]]
[[Category:Royal Norwegian Society of Sciences and Letters]]
[[Category:Royal Norwegian Society of Sciences and Letters]]
[[Category:People from Frogn]]

[[Category:Presidents of the Norwegian Mathematical Society]]
{{norway-scientist-stub}}
{{Europe-mathematician-stub}}

Latest revision as of 14:12, 22 March 2024

Viggo Brun
Born13 October 1885
Lier, Norway
Died15 August 1978 (1978-08-16) (aged 92)
Drøbak, Norway
CitizenshipNorway
Known forBrun's Theorem, Brun Sieve
Scientific career
FieldsNumber Theory

Viggo Brun (13 October 1885 – 15 August 1978) was a Norwegian professor, mathematician and number theorist. [1]

Contributions

[edit]

In 1915, he introduced a new method, based on Legendre's version of the sieve of Eratosthenes, now known as the Brun sieve, which addresses additive problems such as Goldbach's conjecture and the twin prime conjecture. He used it to prove that there exist infinitely many integers n such that n and n+2 have at most nine prime factors, and that all large even integers are the sum of two numbers with at most nine prime factors.[2]

He also showed that the sum of the reciprocals of twin primes converges to a finite value, now called Brun's constant: by contrast, the sum of the reciprocals of all primes is divergent. He developed a multi-dimensional continued fraction algorithm in 1919–1920 and applied this to problems in musical theory. He also served as praeses of the Royal Norwegian Society of Sciences and Letters in 1946.[3]

Biography

[edit]

Brun was born at Lier in Buskerud, Norway. He studied at the University of Oslo and began research at the University of Göttingen in 1910. In 1923, Brun became a professor at the

Viggo Brun (published in 1911)

Technical University in Trondheim and in 1946 a professor at the University of Oslo.[4]

He retired in 1955 at the age of 70 and died in 1978 (at 92 years-old) at Drøbak in Akershus, Norway.[5]

See also

[edit]


Fotnoter

[edit]


References

[edit]
  1. ^ "Viggo Brun". numbertheory.org. 18 June 2003. Retrieved January 1, 2017.
  2. ^ J J O'Connor; E F Robertson. "Viggo Brun". School of Mathematics and Statistics, University of St Andrews, Scotland. Archived from the original on 2017-01-16. Retrieved January 1, 2017.
  3. ^ Bratberg, Terje (1996). "Vitenskapsselskapet". In Arntzen, Jon Gunnar (ed.). Trondheim byleksikon. Oslo: Kunnskapsforlaget. pp. 599–600. ISBN 82-573-0642-8.
  4. ^ "Viggo Brun". Store norske leksikon. Retrieved January 1, 2017.
  5. ^ Bent Birkeland. "Viggo Brun". Norsk biografisk leksikon. Retrieved January 1, 2017.

Other sources

[edit]
[edit]
Academic offices
Preceded by Praeses of the Royal Norwegian Society of Sciences and Letters
1946
Succeeded by