Teiji Takagi

Teiji Takagi (Japanese高木 贞 治; * April 21, 1875 in the village Kazuya near Gifu, † February 19, 1960 in Tokyo ) was a Japanese number theorist.

Life

Takagi grew up in the country and showed early signs of mathematical talent. In 1894 he began his studies at the Imperial University (then the only university in Japan ), where he mainly foreign textbooks made ​​use of, in particular, the algebra of Heinrich Weber. After graduating in 1897, he was selected as one of twelve students for study abroad. He studied in Berlin with Frobenius, Fuchs and black. After reading the just-released " report number " by David Hilbert, who summarized the then state of knowledge of algebraic number theory and promoted, he decided to continue his studies in Göttingen in Hilbert ( 1900 ). Hilbert had, however, after the writing of the report number completely different areas facing ( the foundations of geometry, integral equations ).

1901 Takagi returned back to Japan, assistant professor was now called at his alma mater University of Tokyo. He received his doctorate in 1903 with the efforts made in Göttingen number theoretical studies (his thesis supervisor was present Hilbert ), in which he proved, among others, a conjecture of Leopold Kronecker ( " Kronecker Teenage Dream " ) over abelian extensions of imaginary quadratic number fields. In 1904, he received a full professorship in Tokyo, which he held until his retirement in 1936. From 1904 he also began to write a series of textbooks, which at that time were still missing in Japan.

During the First World War he worked largely isolated and developed his existence theorem of class field theory, where it is based on the works of Heinrich Weber. He wore about before at the International Congress of Mathematicians in 1920 in Strasbourg, where he hardly found resonance as algebraic number theory was then operated mainly in Germany and German mathematicians were excluded by Congress. Takagi published his theory in the same year in the Journal of the University of Tokyo. Its importance but was only recognized by Emil Artin in 1922, which was in turn informed by Carl Ludwig Siegel on Takagi's work, and around the same time by Helmut Hasse, the Kiel lectured on class field theory in 1923 and Takagi's work in a presentation at the meeting of the German Mathematical Society (DMV) 1925 represented in Gdansk and in his class field report in the annual report of the DMV 1926. Takagi was then recognized internationally. He was 1932 Vice President of the International Congress of Mathematicians in Zurich in 1936 and the selection committee for the first Fields Medal. During the Second World War he worked on Japanese Chiffriersystemen ( "Purple" ).

Takagi was married since 1902 and had three sons and five daughters.

To him, the merit is attributed to have created at the beginning of the 20th century through his research and his teaching to Japan's connection to modern mathematics. Among his students and Kenjiro Shoda Shokichi Iyanaga.

Writings

• " Collected Papers ", Springer, 1990 ( with the biography of Iyanaga ), ISBN 3-540-70057-9
• "On a theory of relative abelian number field ", Journal College of Science Imperial University of Tokyo, Bd.41, 1920, p.1 -133
• "On the reciprocity law in an arbitrary algebraic number field ," J. College Science Imp.Univ.Tokio, Bd.44, 1922, p.1 -50
• " Algebraic Number Theory " 1948