**Vojtěch Jarník** was a Czech mathematician who worked in number theory, mathematical analysis, and graph algorithms.

- Jan Urban Jarník (1848-1923) had graduated from the University in Vienna where he had studied Czech, German, French, Italian, English, Sanskrit and comparative grammar of Indo-European languages.
- Jarník attended the First Czech Real Gymnasium, similar to the German Realschule, in Ječná Street in Prague.
- At the Charles University, Jarník attended mathematics lectures delivered by Karel Petr (1868-1950), Bohuslav Hostinsky (1884-1951), Karel Rychlík (1885-1968), Jan Sobotka (1862- 1931), Bohumil Bydzovsky (1880-1969) and Václav Láska (1862-1943).
- Jarník also attended physics lectures by Bohumil Kucera (1874-1921), Václav Posejpal (1874-1935), Vladimír Václav Heinrich (1884-1965) and František Závisška (1879-1945).
- Jarník graduated from the Charles University in 1919.
- After graduating, Jarník was appointed as an assistant to Jan Vojtěch (1879-1953) at the Technical University of Brno.
- Jan Vojtěch, after teaching in secondary schools in Prague, Olomouc, and Brno had taught at the Technical University of Brno from 1916, being appointed as an extraordinary professor on 25 February 1918.
- In Brno, Jarník met Matyáš Lerch who influenced his mathematical development.
- While carrying out his duties in Brno, Jarník continued to work on his doctoral thesis and he submitted On the roots of Bessel functions (Czech) to the Charles University in Prague and, after defending his thesis, was awarded his doctorate in 1921.
- At this time Petr was writing his book Pocet diferenciální (cást analytická) Ⓣ(Differential Calculus) and Jarník helped with proof-reading but also made improvements to the text which Petr acknowledged in the published work.
- The main topic of Jarník's research was number theory.
- Jarník and Landau studied the same problem for curves and surfaces other than circles.
- Another area of number theory which interested Jarník was Diophantine approximation.
- Around 60 of Jarník's 90 papers were written on number theory.
- On 14 March, with Prague covered in snow, Jarník burnt all his correspondence.
- Jarník then had the extremely arduous task of trying to reform and rebuild higher education in the Charles University and in the country as a whole.
- Let us now look at some comments from Jarník's students, the first from before the Nazi takeover of Prague, the second soon after teaching began following the end of World War II.
- Štefan Schwartz entered Charles University in 1932 and began attending Jarník's lectures.
- Jarník did not lecture "slowly", but no rush was ever felt.
- Jarník was then 35 years old.
- However, the fact is that practically all today's Czech mathematicians can be considered directly or indirectly Jarník's students, and that everybody in this country who is engaged in Mathematics has been, to a greater or smaller extent, influenced by Jarník's personality.
- Professor Jarník was aware of the fact that, for the sake of our Mathematics, it was of much greater importance to pass to a large number of young people an affection for Mathematics and to give them firm foundations both in knowledge and methods of scientific work than to educate a few narrow specialists in his own field.
- Perhaps one of the best indications of Jarník's dedication to training young mathematicians is the fact that he supervised the doctoral dissertations of 37 students.
- In situations when much younger and much less experienced colleagues lose their temper, Jarník keeps his head.
- For these rare qualities, Jarník is not only respected and appreciated by all his friends but also they make him really very popular.
- As well as being an editor of Acta Arithmetica from the founding of the journal, Jarník was active in organising university education and scientific research throughout Czechoslovakia.
- As we noted above, Jarník retired from the Charles University in 1968.
- On 16 March 1998 the Faculty of Mathematics and Physics of Charles University, the Union of Czech Mathematicians and Physicists, and the Mathematical Institute of the Academy of Sciences of the Czech Republic jointly organised an international conference to celebrate the centenary of the birth of Vojtech Jarník.

Born 22 December 1897, Prague, Bohemia (now Czech Republic). Died 22 September 1970, Prague, Czechoslovakia (now Czech Republic).

View full biography at MacTutor

Origin Czech Republic

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive