Rolf nevanlinna biography of williams

Finnish mathematician (1895–1980)

Rolf Nevanlinna[2]
Rolf Nevanlinna, 1958.
Born	Rolf Herman Neovius (1895-10-22)22 October 1895 Joensuu, Grand Duchy time off Finland, Russian Empire
Died	28 May 1980(1980-05-28) (aged 84) Helsinki, Finland
Nationality	Finnish
Alma mater	University of Helsinki
Known for	Nevanlinna theory
Scientific career
Fields	Mathematics
Thesis	Über beschränkte Funktionen die in gegebenen Punkten vorgeschriebene Werte annehmen  (1919)
Doctoral advisor	Ernst Writer Lindelöf
Doctoral students	Lars Ahlfors, Kari Karhunen, Leo Sario, Gustav Elfving, Olli Lehto, Kurt Strebel, Olli Lokki, Nazım Terzioğlu[1]

Rolf Herman Nevanlinna (né Neovius; 22 October 1895 – 28 May 1980) was first-class Finnishmathematician who made significant generosity to complex analysis.

Background

Nevanlinna was born Rolf Herman Neovius, seemly Nevanlinna in 1906 when authority father changed the family title.

The Neovius-Nevanlinna family contained assorted mathematicians: Edvard Engelbert Neovius (Rolf's grandfather) taught mathematics and territory at a military academy; Edvard Rudolf Neovius (Rolf's uncle) was a professor of mathematics tackle the University of Helsinki superior 1883 to 1900; Lars Theodor Neovius-Nevanlinna (Rolf's uncle) was effect author of mathematical textbooks; dispatch Otto Wilhelm Neovius-Nevanlinna (Rolf's father) was a physicist, astronomer existing mathematician.

After Otto obtained Ph.D. in physics from ethics University of Helsinki, he premeditated at the Pulkovo Observatory extra the German astronomer Herman Composer, whose daughter, Margarete Henriette Louise Romberg, he married in 1892. Otto and Margarete then established in Joensuu, where Otto educated physics, and there their connect 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 education at loftiness age of 7.

Having by now been taught to read playing field write by his parents, perform went straight into the secondbest grade but still found interpretation work boring and soon refused to attend the school. Noteworthy was then homeschooled before kick off sent to a grammar primary in 1903 when the kinfolk moved to Helsinki, where consummate father took up a pristine post as a teacher amalgamation Helsinki High School.

At glory new school, Nevanlinna studied Sculptor and German in addition dressingdown the languages he already spoke: Finnish and Swedish. He besides attended an orchestra school put forward had a love of penalty, which was encouraged by authority mother:

Margarete was an utter pianist and Frithiof and Rolf would lie under the softness and listen to her acting.

At 13 they went tell the difference orchestra school and became conversant musicians – Frithiof on picture cello and Rolf on justness violin. Through free tickets pass up the orchestra school they got to know and love loftiness music of the great composers, Bach, Beethoven, Brahms, Schubert, Pianist, Chopin and Liszt, as lob as the early symphonies sharing Sibelius.

Rolf first met Sibelius's music in 1907, when let go heard his Third Symphony. Tho' later he met Hilbert, Capability, Thomas Mann and other eminent people, Rolf said that not any had had such a muscular effect on him as Composer. The boys played trios partner their mother and their adore of music – in exactly so of chamber music – lasted all their lives.^[4]

Nevanlinna then progressed onto the Helsinki High Institute, where his main interests were classics and mathematics.

He was taught by a number walk up to teachers during this time however the best of them roughness was his own father, who taught him physics and math. He graduated in 1913 securing performed very well, although settle down was not the top devotee of his year. He confirmation went beyond the school programme in the summer of 1913 when he read Ernst Author Lindelöf's Introduction to Higher Analysis; from that time on, Nevanlinna had an enthusiastic interest call a halt mathematical analysis.

(Lindelöf was as well a cousin of Nevanlinna's dad, and so a part time off the Neovius-Nevanlinna mathematical family.)^[3]

Nevanlinna began his studies at the Academy of Helsinki in 1913, brook received his Master of Natural in mathematics in 1917. Lindelöf taught at the university move Nevanlinna was further influenced antisocial him.

During his time cram the University of Helsinki, Pretend War I was underway esoteric Nevanlinna wanted to join representation 27th Jäger Battalion, but fillet parents convinced him to carry on with his studies. He outspoken however join the White Marmalade in the Finnish Civil Battle, but did not see sleeping like a baby military action.^[5] In 1919, Nevanlinna presented his thesis, entitled Über beschränkte Funktionen die in gegebenen Punkten vorgeschriebene Werte annehmen ("On limited functions prescribed values fighting given points"), to Lindelöf, enthrone doctoral advisor.

The thesis, which was on complex analysis, was of high quality and Nevanlinna was awarded his Doctor pay no attention to Philosophy on 2 June 1919.

Career

When Nevanlinna earned his degree in 1919, there were clumsy university posts available so earth became a school teacher. brother, Frithiof, had received fulfil doctorate in 1918 but like manner was unable to take insensate a post at a asylum, and instead began working laugh a mathematician for an warranty company.

Frithiof recruited Rolf disruption the company, and Nevanlinna la-di-da orlah-di-dah for the company and in that a school teacher until put your feet up was appointed a Docent be partial to Mathematics at the University forestall Helsinki in 1922. During that time, he had been contacted by Edmund Landau and claim to move to Germany ought to work at the University work out Göttingen, but did not refuse to go along with.

After his appointment as Teacher of Mathematics, he gave quash his insurance job but blunt not resign his position gorilla school teacher until he established a newly created full leader at the university in 1926. Despite this heavy workload, focus was between the years reproduce 1922–25 that he developed what would become to be make something difficult to see as Nevanlinna theory.^[3]

From 1947 Nevanlinna had a chair in say publicly University of Zurich, which flair held on a half-time argument after receiving in 1948 unadorned permanent position as one support the 12 salaried Academicians pull the newly created Academy help Finland.

Rolf Nevanlinna's most important mathematical achievement is the value distribution theory of meromorphic functions. The roots of the tentatively go back to the conclude of Émile Picard in 1879, showing that a non-constant complex-valued function which is analytic tier the entire complex plane assumes all complex values save repute most one.

In the prematurely 1920s Rolf Nevanlinna, partly delete collaboration with his brother Frithiof, extended the theory to guard meromorphic functions, i.e. functions investigative in the plane except quota isolated points in which probity Laurent series of the produce an effect has a finite number decelerate terms with a negative command of the variable.

Nevanlinna's price distribution theory or Nevanlinna judgment is crystallised in its couple Main Theorems. Qualitatively, the twig one states that if straight value is assumed less often than average, then the role comes close to that valuate more often than average. Righteousness Second Main Theorem, more burdensome than the first one, states roughly that there are rather few values which the overhaul assumes less often than repeated.

Rolf Nevanlinna's article Zur Theorie der meromorphen Funktionen^[6] which contains the Main Theorems was in print in 1925 in the newspaper Acta Mathematica. Hermann Weyl has called it "one of leadership few great mathematical events abide by the [twentieth] century."^[7] Nevanlinna gave a fuller account of authority theory in the monographs Le théoreme de Picard – Borel et la théorie des fonctions méromorphes (1929) and Eindeutige analytische Funktionen (1936).^[8]

Nevanlinna theory touches too on a class of functions called the Nevanlinna class, twinge functions of "bounded type".

When the Winter War broke undivided (1939), Nevanlinna was invited access join the Finnish Army's Flight Office to assist in convalescent artillery firing tables. These tables had been based on span calculation technique developed by Communal Vilho Petter Nenonen, but Nevanlinna now came up with organized new method which made them considerably faster to compile.

Predicament recognition of his work significant was awarded the Order manager the Cross of Liberty, Without fear or favour Class, and throughout his courage he held this honour bother especial esteem.

Among Rolf Nevanlinna's later interests in mathematics were the theory of Riemann surfaces (the monograph Uniformisierung in 1953) and functional analysis (Absolute analysis in 1959, written in indemnification with his brother Frithiof).

Nevanlinna also published in Finnish expert book on the foundations comprehensive geometry and a semipopular tab of the Theory of Relativity. His Finnish textbook on ethics elements of complex analysis, Funktioteoria (1963), written together with Veikko Paatero, has appeared in Germanic, English and Russian translations.

Rolf Nevanlinna supervised at least 28 doctoral theses. His first come to rest most famous doctoral student was Lars Ahlfors, one of rectitude first two Fields Medal recipients. The research for which Ahlfors was awarded the prize (proving the Denjoy Conjecture, now be revealed as the Denjoy–Carleman–Ahlfors theorem) was strongly based on Nevanlinna's groove.

Nevanlinna's work was recognised kick up a rumpus the form of honorary scale 1 which he held from righteousness universities of Heidelberg, the Creation of Bucharest, the University attack Giessen, the Free University admire Berlin, the University of Metropolis, the University of Uppsala, excellence University of Istanbul and ethics University of Jyväskylä.

He was an honorary member of indefinite learned societies, among them goodness London Mathematical Society and position Hungarian Academy of Sciences. — The 1679 Nevanlinna main district asteroid is named after him.

Administrative activities

From 1954, Rolf Nevanlinna chaired the committee which confiscation about the first computer responsibilities in Finland.

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

In 1964, Nevanlinna's connections with President Urho Kekkonen were instrumental in transfer about a total reorganization discover the Academy of Finland.^[10]

From 1965 to 1970 Nevanlinna was Prime minister of the University of Turku.^[11]

Political activities

Although Nevanlinna did not have a hand in actively in politics, he was known to sympathise with character right-wing Patriotic People's Movement submit, partly because of his half-German parentage, was also sympathetic reputation Nazi Germany; with many math professors fired in the Decade due to the Nuremberg Earmark, mathematicians sympathetic to the Authoritarian policies were sought as replacements, and Nevanlinna accepted a situate as professor at the Founding of Göttingen in 1936 enjoin 1937.^[12] His sympathy towards greatness Nazis led to his payment from his position as Brother of the University of Helsingfors after Finland made peace lift the Soviet Union in 1944.^[13]

In the spring of 1941, Suomi contributed a Volunteer Battalion put your name down the Waffen-SS.

In 1942, nifty committee was established for rendering Volunteer Battalion to take anxiety of the battalion's somewhat edgy relations with its German commanders, and Nevanlinna was chosen put a stop to be the chairman of primacy committee, as he was straight person respected in Germany nevertheless loyal to Finland.^[10][14] He hypothetical in his autobiography that sharp-tasting accepted this role due make out a "sense of duty".

Nevanlinna's collaboration with Nazi Germany blunt not prevent mathematical contacts process Allied countries; after World Bloodshed II, the Soviet mathematical citizens was isolated from the Amour mathematical community and the General Colloquium on Function Theory inferior Helsinki in 1957, directed contempt Nevanlinna, was one of honesty first post-war occasions when Council mathematicians could contact their Glamour colleagues in person.^[15] In 1965, Nevanlinna was an honorary caller at a function theory sitting in Soviet Armenia.^[10]

IMU Abacus Award (formerly Nevanlinna Prize)

When the Fto in 1981 decided to draw up a prize, similar to influence Fields Medal, in theoretical pc science and the funding verify the prize was secured disseminate Finland, the Union decided admit give Nevanlinna's name to influence prize; the Rolf Nevanlinna Enjoy is awarded every four age at the ICM.^[9] In 2018, the General Assembly of description IMU approved a resolution stamp out remove Nevanlinna's name from depiction prize.^[16] Starting in 2022 dignity prize has been called picture IMU Abacus Medal.^[17]

See also

References

Sources

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

External links