Olli Erkki Lehto (30 May 1925 in

Helsinki Helsinki ( or ; ; sv, Helsingfors, ) is the Capital city, capital, primate city, primate, and List of cities and towns in Finland, most populous city of Finland. Located on the shore of the Gulf of Finland, it is the seat of the region of U ...

— 31 December 2020) was a Finnish mathematician, specializing in geometric function theory, and a

chancellor Chancellor ( la, cancellarius) is a title of various official positions in the governments of many nations. The original chancellors were the of Roman courts of justice—ushers, who sat at the or lattice work screens of a basilica or law cou ...

of the

University of Helsinki The University of Helsinki ( fi, Helsingin yliopisto, sv, Helsingfors universitet, abbreviated UH) is a public research university located in Helsinki, Finland since 1829, but founded in the city of Turku (in Swedish ''Åbo'') in 1640 as the ...

. Lehto earned his PhD in 1949 from the University of Helsinki under

Rolf Nevanlinna Rolf Herman Nevanlinna (né Neovius; 22 October 1895 – 28 May 1980) was a Finnish mathematician who made significant contributions to complex analysis. Background Nevanlinna was born Rolf Herman Neovius, becoming Nevanlinna in 1906 when his fat ...

with thesis ''Anwendung orthogonaler Systeme auf gewisse funktionentheoretische Extremal- und Abbildungsprobleme''. At the University of Helsinki, Lehto was from 1961 to 1988 a professor, from 1978 the dean of science, from 1983 the rector, and from 1988 to 1993 the chancellor. From 1983 to 1990 he was Secretary of the International Mathematical Union. In 1962 he became a member of the

Finnish Academy of Science and Letters The Finnish Academy of Science and Letters (Finnish ''Suomalainen Tiedeakatemia''; Latin ''Academia Scientiarum Fennica'') is a Finnish learned society. It was founded in 1908 and is thus the second oldest academy in Finland. The oldest is the Fi ...

(Suomalainen Tiedeakatemia). In 1968 he was elected member of the

Finnish Society of Sciences and Letters The Finnish Society of Sciences and Letters is a Finnish academy for natural sciences, social sciences and humanities. It is known in Latin as Societas Scientiarum Fennica, in Swedish as Finska Vetenskaps-Societeten, and in Finnish as Suomen Tiede ...

and in 1988 he became honorary member of the same society. He was a member of the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters ( no, Det Norske Videnskaps-Akademi, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick Univer ...

from 1986. In 1975 he was given by the President of Finland the honorary title "Academician of Science" (Tieteen akateemikko). Lehto was the chief organizer of the

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the Nevanlinna Prize (to be rename ...

(ICM) in Helsinki in 1978 and an invited speaker of the ICM in Moscow in 1966 with lecture ''Quasiconformal mappings in the plane''. He was elected a Fellow of the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

. In 2001 Lehto published a biography of his mentor Rolf Nevanlinna.

Selected works

* ''Univalent functions and Teichmüller Spaces.'' Springer, Graduate Texts in Mathematics, 1987. * with Kaarlo Virtanen: ''Quasikonforme Abbildungen.'' Springer 1965, Grundlehren der Mathematischen Wissenschaften, 2nd edition: ''Quasiconformal mappings in the plane.'' Springer 1973. * ** * ''Tieteen aatelia:

Lorenz Lindelöf Lorenz is an originally German name derived from the Roman surname Laurentius (disambiguation), Laurentius, which means "from Laurentum". Given name People with the given name Lorenz include: * Prince Lorenz of Belgium (born 1955), member of th ...

Ernst Lindelöf Ernst is both a surname and a given name, the German, Dutch, and Scandinavian form of Ernest. Notable people with the name include: Surname * Adolf Ernst (1832–1899) German botanist known by the author abbreviation "Ernst" * Anton Ernst (1975- ...

.'' Otava, Helsinki 2008 (Finnish). * * 2015 pbk reprint

References

External links

Kirjailijat – Olli Lehto.
Otava. {{DEFAULTSORT:Lehto, Olli 1925 births Finnish mathematicians University of Helsinki alumni Academic staff of the University of Helsinki Fellows of the American Mathematical Society Foreign Members of the Russian Academy of Sciences Members of the Norwegian Academy of Science and Letters 2020 deaths Rectors of the University of Helsinki Chancellors of the University of Helsinki