Jérôme Franel (1859–1939) was a Swiss

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

who specialised in

analytic number theory In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Peter Gustav Lejeune Dirichlet's 1837 introduction of Diric ...

. He is mainly known through a 1924 paper, in which he establishes the equivalence of the

Riemann hypothesis In mathematics, the Riemann hypothesis is the conjecture that the Riemann zeta function has its zeros only at the negative even integers and complex numbers with real part . Many consider it to be the most important unsolved problem in ...

to a statement on the size of the discrepancy in the

Farey sequence In mathematics, the Farey sequence of order ''n'' is the sequence of completely reduced fractions, either between 0 and 1, or without this restriction, which when in lowest terms have denominators less than or equal to ''n'', arranged in ord ...

s, and which is directly followed (in the same journal) by a development on the same subject by

Edmund Landau Edmund Georg Hermann Landau (14 February 1877 – 19 February 1938) was a German mathematician who worked in the fields of number theory and complex analysis. Biography Edmund Landau was born to a Jewish family in Berlin. His father was Leopold ...

. Jérôme Franel was a citizen ("bourgeois") of

Provence Provence (, , , , ; oc, Provença or ''Prouvènço'' , ) is a geographical region and historical province of southeastern France, which extends from the left bank of the lower Rhône to the west to the Italian border to the east; it is bor ...

(Vaud, Switzerland). He was born on November 29, 1859 in Travers (Neuchâtel, Suisse), and died in

Zürich Zürich () is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zürich. It is located in north-central Switzerland, at the northwestern tip of Lake Zürich. As of January 2020, the municipality has 43 ...

on November 21, 1939.

George Pólya George Pólya (; hu, Pólya György, ; December 13, 1887 – September 7, 1985) was a Hungarian mathematician. He was a professor of mathematics from 1914 to 1940 at ETH Zürich and from 1940 to 1953 at Stanford University. He made fundamental ...

said that he was an especially attractive kind of person and a very good teacher, but that, since he spent most of his time teaching, and reading French literature (for which he had a passion), he had no time left for research. After his retirement he worked on the

Childhood and schools

Jerôme Franel spent his first years with his 12 brothers and sisters in Travers. He graduated with a sciences highschool diploma from the "Ecole industrielle" in

Lausanne , neighboring_municipalities= Bottens, Bretigny-sur-Morrens, Chavannes-près-Renens, Cheseaux-sur-Lausanne, Crissier, Cugy, Écublens, Épalinges, Évian-les-Bains (FR-74), Froideville, Jouxtens-Mézery, Le Mont-sur-Lausanne, Lugrin (FR-74), ...

. He then studied at the Politechnikum in Zürich, and in Berlin where he attended courses given by

Weierstrass Karl Theodor Wilhelm Weierstrass (german: link=no, Weierstraß ; 31 October 1815 – 19 February 1897) was a German mathematician often cited as the "father of modern mathematical analysis, analysis". Despite leaving university without a degree, ...

, Kronecker and Kummer, and finally in Paris where he attended courses by

Hermite Charles Hermite () FRS FRSE MIAS (24 December 1822 – 14 January 1901) was a French mathematician who did research concerning number theory, quadratic forms, invariant theory, orthogonal polynomials, elliptic functions, and algebra. Hermi ...

. On September 15, 1883, he was awarded a science bachelor's degree ("licence") from the Paris Academy.

Career

Franel taught then for two years at the "Ecole industrielle" in Lausanne. On April 1, 1886, then only 26 years old, he was appointed to the Chair of Mathematics in the French language at the Politechnikum in Zürich by the Federal Council of Switzerland. In 1896 he was a member of the organizing committee of the first

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 ...

, which took place in Zürich in 1897. He delivered the introductory lecture to the congress, written by

Henri Poincaré Jules Henri Poincaré ( S: stress final syllable ; 29 April 1854 – 17 July 1912) was a French mathematician, theoretical physicist, engineer, and philosopher of science. He is often described as a polymath, and in mathematics as "The ...

, but who was then unwell. In 1905 the

University of Zürich The University of Zürich (UZH, german: Universität Zürich) is a public research university located in the city of Zürich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 f ...

awarded him an honorary doctorate, and the city of Zürich awarded him honorary citizenship ("Bourgeoisie"). Under his presidency (1905-1909) the school was entirely restructured, and it was probably through his insistence (in particular, through a 1907 speech) that the Polytechnikum finally obtained (in 1908) the right to award a doctoral degree like the University did.For instance

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...

1905 doctoral degree was delivered by the University of Zürich, and not by the Polytechnikum where he studied. The first doctorates were awarded in 1909. He retired in 1929.

References and notes

* Jérôme Franel's necrology, by

Louis Kollros Louis Kollros (7 May 1878, La Chaux-de-Fonds – 19 June 1959, Zurich) was a Swiss mathematician. From 1909 to 1948 he was a professor ordinarius of geometry at ETH Zurich. Kollros, the son of a baker, was from 1896 as a student of mathematics ...

, in: ''Verhandlungen der Schweizerischen Naturforschenden Gesellschaft'' 120 (1940), 439-444
Read french document online

External link

{{DEFAULTSORT:Franel, Jerome 19th-century Swiss mathematicians 20th-century Swiss mathematicians ETH Zurich faculty ETH Zurich alumni Humboldt University of Berlin alumni Number theorists 1859 births 1939 deaths