Camille Jordan

Marie Ennemond Camille Jordan, called Camille Jordan ( born January 5, 1838 in Lyon, † January 21, 1922 in Paris) was a French mathematician.

Jordan's father was an engineer and his mother a sister of the painter Pierre Puvis de Chavannes. He studied from 1855 at the École Polytechnique in Paris, and then worked as an engineer, first in Privas, then in Chalon -sur -Saône and finally in Paris. Besides, he found sufficient time to operate mathematical research. In 1860 he received his doctorate in Victor Puiseux at the Faculté des Sciences ( Sorbonne ) in Paris. In 1876 he became professor of analysis at the École Polytechnique, where he was an examiner from 1873, and also in 1883 a professor at the College de France. In 1912 he went into retirement.

In 1916 he became president of the Academy of Sciences, member of which was since 1881.

He has made fundamental contributions to the analysis, group theory and topology. To this day, the term Jordan curve on his name. His proof of the Jordan curve theorem has been criticized in 1905 by Oswald Veblen and later it was generally considered that Young gave the first rigorous proof. This has been called into question by Thomas C. Hales, 2007. In particular, Hales looks at one of the main criticisms of the lack of evidence for polygons, as unfounded, as this part of the proof is relatively easy to establish.

His textbook of group theory in the 19th century was very influential (it was the first book on group theory ) as well as his analysis textbook ( Cours d'Analyse ). The Jordan normal form in linear algebra and the set of Jordan - Hölder in group theory are named after him.

Felix Klein used to give his listeners the best in his lecture on group theory the following story:

" On the memorable Congress of Mathematicians in Paris in 1900 was commemorated in a simple ceremony all famous mathematician, who had passed away in the last ten years. Among other things, the group theorist Camille Jordan, born in 1838, died on November 7, 1898 called. As rose in the last rows a gaunt figure to announce the meeting that the particulars of his death date at least the year could not vote because he was still alive. "

Klein and Sophus Lie visited Paris in 1870, not least in order to study its group-theoretical concepts in Jordan.

For his book on group theory, he was awarded the Poncelet Prize of the Academie des Sciences. In 1890 he became an officer of the Legion of Honour. In 1920 he was Honorary President of the International Congress of Mathematicians in Strasbourg.

He was married to Marie -Isabelle Munet since 1862, daughter of the mayor of Lyon. With her he had eight children. Three of his six sons fell in the First World War. His son Camille was a minister, his son Edouard professor of history at the Sorbonne.

Writings

• Oeuvres de Camille Jordan, Paris, 4 volumes, 1961-1964 (Editor Jean Dieudonné )
• Traité des substitutions et des équations algébriques, Gauthier -Villars 1870
• Cours d' analyze de l' École polytechnique, 3 volumes, Gauthier -Villars 1893 to 1896 ( first edition 1882-1887 )