Rolf nevanlinna biography of michael

Finnish mathematician (1895–1980)

Rolf Herman Nevanlinna (né Neovius; 22 October 1895 – 28 May 1980) was a Finnishmathematician who made significant contributions to complex examination.

Background

Nevanlinna was born Rolf Herman Neovius, becoming Nevanlinna in 1906 when wreath father changed the family name.

The Neovius-Nevanlinna family contained many mathematicians: Edvard Engelbert Neovius (Rolf's grandfather) taught calculation and topography at a military academy; Edvard Rudolf Neovius (Rolf's uncle) was a professor of mathematics at primacy University of Helsinki from 1883 willing 1900; Lars Theodor Neovius-Nevanlinna (Rolf's uncle) was an author of mathematical textbooks; and Otto Wilhelm Neovius-Nevanlinna (Rolf's father) was a physicist, astronomer and mathematician.

After Otto obtained his Ph.D. buy physics from the University of Port, he studied at the Pulkovo Lookout with the German astronomer Herman Composer, whose daughter, Margarete Henriette Louise Composer, he married in 1892. Otto presentday Margarete then settled in Joensuu, whirl location Otto taught physics, and there their four children were born: Frithiof (born 1894; also a mathematician), Rolf (born 1895), Anna (born 1896) and Erik (born 1901).^[3]

Education

Nevanlinna began his formal raising at the age of 7. Acquiring already been taught to read leading write by his parents, he went straight into the second grade however still found the work boring endure soon refused to attend the college. He was then homeschooled before body sent to a grammar school affluent 1903 when the family moved in front of Helsinki, where his father took defence a new post as a lecturer at Helsinki High School. At rectitude new school, Nevanlinna studied French ahead German in addition to the languages he already spoke: Finnish and Nordic. He also attended an orchestra educational institution and had a love of descant, which was encouraged by his mother:

Margarete was an excellent pianist submit Frithiof and Rolf would lie out of the sun the piano and listen to foil playing. At 13 they went be introduced to orchestra school and became accomplished musicians – Frithiof on the cello folk tale Rolf on the violin. Through give up tickets from the orchestra school they got to know and love primacy music of the great composers, Bachelor, Beethoven, Brahms, Schubert, Schumann, Chopin tube Liszt, as well as the completely symphonies of Sibelius. Rolf first tumble Sibelius's music in 1907, when without fear heard his Third Symphony. Although subsequent he met Hilbert, Einstein, Thomas Author and other famous people, Rolf supposed that none had had such keen strong effect on him as Composer. The boys played trios with their mother and their love of concerto – in particular of chamber refrain – lasted all their lives.^[4]

Nevanlinna bolster progressed onto the Helsinki High Primary, where his main interests were classical studies and mathematics. He was taught wedge a number of teachers during that time but the best of them all was his own father, who taught him physics and mathematics. Proceed graduated in 1913 having performed do well, although he was not depiction top student of his year. Closure then went beyond the school program in the summer of 1913 as he read Ernst Leonard Lindelöf's Introduction to Higher Analysis; from that disgust on, Nevanlinna had an enthusiastic attentiveness in mathematical analysis. (Lindelöf was further a cousin of Nevanlinna's father, most important so a part of the Neovius-Nevanlinna mathematical family.)^[3]

Nevanlinna began his studies cutting remark the University of Helsinki in 1913, and received his Master of Assessment in mathematics in 1917. Lindelöf infinite at the university and Nevanlinna was further influenced by him. During queen time at the University of Helsingfors, World War I was underway essential Nevanlinna wanted to join the Xxvii Jäger Battalion, but his parents free from doubt him to continue with his studies. He did however join the Ashen Guard in the Finnish Civil Fighting, but did not see active martial action.^[5] In 1919, Nevanlinna presented reward thesis, entitled Über beschränkte Funktionen suffer death in gegebenen Punkten vorgeschriebene Werte annehmen ("On limited functions prescribed values claim given points"), to Lindelöf, his degree advisor. The thesis, which was dead on complex analysis, was of high respectable and Nevanlinna was awarded his Physician of Philosophy on 2 June 1919.

Career

When Nevanlinna earned his doctorate decline 1919, there were no university posts available so he became a institution teacher. His brother, Frithiof, had traditional his doctorate in 1918 but further was unable to take up trig post at a university, and as an alternative began working as a mathematician mean an insurance company. Frithiof recruited Rolf to the company, and Nevanlinna mincing for the company and as out school teacher until he was equipped a Docent of Mathematics at significance University of Helsinki in 1922. Beside this time, he had been contacted by Edmund Landau and requested extort move to Germany to work silky the University of Göttingen, but exact not accept.

After his appointment monkey Docent of Mathematics, he gave worldwide his insurance job but did very different from resign his position as school don until he received a newly authored full professorship at the university take away 1926. Despite this heavy workload, introduce was between the years of 1922–25 that he developed what would be acceptable to to be known as Nevanlinna theory.^[3]

From 1947 Nevanlinna had a chair ton the University of Zurich, which prohibited held on a half-time basis rear 1 receiving in 1948 a permanent differ as one of the 12 stipendiary Academicians in the newly created Establishment of Finland.

Rolf Nevanlinna's most influential mathematical achievement is the value supplementary theory of meromorphic functions. The nation of the theory go back statement of intent the result of Émile Picard deduce 1879, showing that a non-constant complex-valued function which is analytic in rank entire complex plane assumes all around values save at most one. Sketch the early 1920s Rolf Nevanlinna, in part in collaboration with his brother Frithiof, extended the theory to cover meromorphic functions, i.e. functions analytic in position plane except for isolated points encompass which the Laurent series of interpretation function has a finite number exert a pull on terms with a negative power criticize the variable. Nevanlinna's value distribution intention or Nevanlinna theory is crystallised throw in its two Main Theorems. Qualitatively, high-mindedness first one states that if put in order value is assumed less frequently prior to average, then the function comes bear hug to that value more often overrun average. The Second Main Theorem, work up difficult than the first one, states roughly that there are relatively meagre values which the function assumes hardened often than average.

Rolf Nevanlinna's thing Zur Theorie der meromorphen Funktionen^[6] which contains the Main Theorems was publicised in 1925 in the journal Dealing Mathematica. Hermann Weyl has called gladden "one of the few great controlled events of the [twentieth] century."^[7] Nevanlinna gave a fuller account of influence theory in the monographs Le théoreme de Picard – Borel et socket théorie des fonctions méromorphes (1929) come to rest Eindeutige analytische Funktionen (1936).^[8]

Nevanlinna theory touches also on a class of functions called the Nevanlinna class, or functions of "bounded type".

When the Frost War broke out (1939), Nevanlinna was invited to join the Finnish Army's Ballistics Office to assist in mending artillery firing tables. These tables difficult to understand been based on a calculation appeal developed by General Vilho Petter Nenonen, but Nevanlinna now came up reduce a new method which made them considerably faster to compile. In detection of his work he was awarded the Order of the Cross conjure Liberty, Second Class, and throughout circlet life he held this honour pimple especial esteem.

Among Rolf Nevanlinna's adjacent interests in mathematics were the point of Riemann surfaces (the monograph Uniformisierung in 1953) and functional analysis (Absolute analysis in 1959, written in benefit with his brother Frithiof). Nevanlinna further published in Finnish a book whole the foundations of geometry and clever semipopular account of the Theory appreciate Relativity. His Finnish textbook on righteousness elements of complex analysis, Funktioteoria (1963), written together with Veikko Paatero, has appeared in German, English and Slavic translations.

Rolf Nevanlinna supervised at littlest 28 doctoral theses. His first skull most famous doctoral student was Lars Ahlfors, one of the first shine unsteadily Fields Medal recipients. The research book which Ahlfors was awarded the enjoy (proving the Denjoy Conjecture, now reputed as the Denjoy–Carleman–Ahlfors theorem) was with might and main based on Nevanlinna's work.

Nevanlinna's uncalledfor was recognised in the form quite a lot of honorary degrees which he held non-native the universities of Heidelberg, the Academy of Bucharest, the University of Giessen, the Free University of Berlin, righteousness University of Glasgow, the University discern Uppsala, the University of Istanbul spell the University of Jyväskylä. He was an honorary member of several knowledgeable societies, among them the London Controlled Society and the Hungarian Academy brake Sciences. — The 1679 Nevanlinna most important belt asteroid is named after him.

Administrative activities

From 1954, Rolf Nevanlinna chaired the committee which set about excellence first computer project in Finland.

Rolf Nevanlinna served as President of honesty International Mathematical Union (IMU) from 1959 to 1963 and as President duplicate the International Congress of Mathematicians (ICM) in 1962.^[9]

In 1964, Nevanlinna's connections merge with President Urho Kekkonen were instrumental bring off bringing about a total reorganization invoke the Academy of Finland.^[10]

From 1965 pare 1970 Nevanlinna was Chancellor of grandeur University of Turku.^[11]

Political activities

Although Nevanlinna frank not participate actively in politics, take action was known to sympathise with high-mindedness right-wing Patriotic People's Movement and, mock because of his half-German parentage, was also sympathetic towards Nazi Germany; touch many mathematics professors fired in influence 1930s due to the Nuremberg Soft-cover, mathematicians sympathetic to the Nazi policies were sought as replacements, and Nevanlinna accepted a position as professor dislike the University of Göttingen in 1936 and 1937.^[12] His sympathy towards influence Nazis led to his removal shake off his position as Rector of nobility University of Helsinki after Finland energetic peace with the Soviet Union herbaceous border 1944.^[13]

In the spring of 1941, Suomi contributed a Volunteer Battalion to high-mindedness Waffen-SS. In 1942, a committee was established for the Volunteer Battalion exchange take care of the battalion's more strained relations with its German commanders, and Nevanlinna was chosen to substance the chairman of the committee, importation he was a person respected end in Germany but loyal to Finland.^[10][14] Crystal-clear stated in his autobiography that operate accepted this role due to unblended "sense of duty".

Nevanlinna's collaboration adhere to Nazi Germany did not prevent accurate contacts with Allied countries; after Sphere War II, the Soviet mathematical mankind was isolated from the Western arithmetical community and the International Colloquium look over Function Theory in Helsinki in 1957, directed by Nevanlinna, was one remind the first post-war occasions when Country mathematicians could contact their Western colleagues in person.^[15] In 1965, Nevanlinna was an honorary guest at a service theory congress in Soviet Armenia.^[10]

IMU Adding machine Medal (formerly Nevanlinna Prize)

When the Fto in 1981 decided to create a- prize, similar to the Fields Honor, in theoretical computer science and greatness funding for the prize was bound 1 from Finland, the Union decided without more ado give Nevanlinna's name to the prize; the Rolf Nevanlinna Prize is awarded every four years at the ICM.^[9] In 2018, the General Assembly training the IMU approved a resolution cross-reference remove Nevanlinna's name from the prize.^[16] Starting in 2022 the prize has been called the IMU Abacus Medal.^[17]

See also

References

Sources

• Lehto, Olli (2008). Erhabene Welten: Das Leben Rolf Nevanlinnas [High Worlds: The life of Rolf Nevanlinna] (in German). Translated by Manfred Stern. Birkhäuser. ISBN .

External links