Harald Bergström (1 April 1908 – 23 May 2001) was a Swedish mathematician, specializing in probability theory.

Education and career

Harald Bergström studied mathematics, physics and chemistry at the

Uppsala University Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. Initially fou ...

and received in 1931 his master's degree. From 1932 to 1934 he taught at secondary schools and then worked as a research assistant at the

. There he received his Ph.D. in 1938 and taught until 1945. In 1946 he moved to

Chalmers University of Technology Chalmers University of Technology (, commonly referred to as Chalmers) is a private university, private research university located in Gothenburg, Sweden. Chalmers focuses on engineering and science, but more broadly it also conducts research ...

in Göteborg, where in 1949 he was appointed a professor of applied mathematics. In 1960 he was also appointed a professor for numerical analysis and mathematical statistics. In 1974 he retired as professor emeritus. At the University of Uppsala, Harald Bergström did research mainly on

algebraic number fields In mathematics, an algebraic number field (or simply number field) is an extension field K of the field (mathematics), field of rational numbers such that the field extension K / \mathbb has Degree of a field extension, finite degree (and hence ...

and related topics. After his move to Chalmers University of Technology, he focused on probability theory and statistics. He was supervisor to Peter Jagers. He made important contributions to

central limit theorem In probability theory, the central limit theorem (CLT) states that, under appropriate conditions, the Probability distribution, distribution of a normalized version of the sample mean converges to a Normal distribution#Standard normal distributi ...

s and the theory of alpha stable distributions. The widely used Bergström's inequality is named, amongst others, after him. He was an

invited speaker at the International Congress of Mathematicians An invitation system is a method of encouraging people to join an organization, such as a Club (organization), club or a website. In regular society, it refers to any system whereby new members are chosen; they cannot simply apply. In relation to w ...

in 1936 at Oslo and in 1950 at Cambridge, Massachusetts. In 1973 Chalmers University of Technology published a book of essays in honour of his sixty-fifth birthday. Peter Jagers, Lennart Råde (eds.): ''Mathematics and statistics. Essays in honour of Harald Bergström''. On the occasion of the 65th birthday of Harald Bergström. Chalmers Institute of Technology, Göteborg, 1973

Selected publications

Books

* ''Limit Theorems for Convolutions.'' Almqvist och Wicksell, Stockholm, und Wiley, New York 1963.
''Weak Convergence of Measures.''
Academic Press, New York 1982.

Articles

* ''Zur Theorie der biquadratischen Zahlkörper. Die Arithmetik auf klassenkörpertheoretischer Grundlage.'' Dissertation. In: ''Nova Acta Regiae Societatis Scientiarum Upsaliensis.'' Series 4, Volume 10, No. 8. Almqvist & Wiksell, Uppsala 1937. * ''Über die Methode von Woronoj zur Berechnung einer Basis eines kubischen Zahlkörpers.'' In: ''Arkiv för matematik, astronomi och fysik.'' Volume 25B, No. 26. Almqvist & Wiksell, Stockholm 1937. * ''Vereinfachter Beweis des Hauptidealsatzes der Klassenkörpertheorie.'' In: ''Arkiv för matematik, astronomi och fysik.'' Volume 29B, No. 6. Almqvist & Wiksell, Stockholm 1943. * ''Struktur der Erweiterungen abelscher Gruppen.'' In: ''Arkiv för matematik, astronomi och fysik.'' Volume 30, No. 4. Almqvist & Wiksell, Stockholm 1944. * ''On the central limit theorem.'' Scandinavian Actuarial Journal Vol. 27, 1944. * ''On the central limit theorem in the space R_k, k > 1'' Scandinavian Actuarial Journal Vol. 28, 1945, pp. 106–127. * ''On the central limit theorem in the case of not equally distributed random variables.'' Scandinavian Actuarial Journal Vol. 32, 1949, pp. 37–62. * ''On some Expansions of stable distribution functions.'' In: ''Arkiv för matematik.'' Vol. 2, No. 18. Almqvist & Wiksell, Stockholm 1952, pp. 375–378. * ''Eine Theorie der stabilen Verteilungsfunktionen.'' In: ''Archiv der Mathematik.'' Volume 2, 1953, pp. 380–391. * ''On the limit theorem for convolutions of distribution functions.'' In: ''Journal für die Reine und Angewandte Mathematik.''Part 1
1957 Vol. 198, pp. 121–142.
Part 2
1958 Vol. 199, pp. 1–22. *

References

External links

* {{DEFAULTSORT:Bergstrom, Harald 1908 births 2001 deaths 20th-century Swedish mathematicians Uppsala University alumni Academic staff of Uppsala University Academic staff of the Chalmers University of Technology People from Karlsborg Municipality Probability theorists