Kubota Tadahiko

Kubota Tadahiko ( Japanese 窪 田 忠彦 ; born February 27, 1885 in Shiba , Tokyo , † October 31, 1952 in Tokyo ) was a Japanese mathematician and university professor .

Life

Kubota studied mathematics at the University of Tokyo , where he graduated in 1908. He then taught until 1911 at the First University of Tokyo and from 1911 as an assistant professor at the University of Tōhoku in Sendai . After further studies in Europe and his habilitation from 1915 until his retirement in 1946, he held a professorship there. From 1948 to 1952 he headed the Institute for Mathematical Statistics in Tokyo.

Kubota made a great contribution to the training of mathematicians and was also active in organizing science.

Research activity

Kubota's mathematical research extended to several areas, not least to analysis , calculus of variations and kinematics . Above all, however, he did research in the field of geometry , where he wrote numerous monographs and had the reputation of a recognized geometer. Here he worked, among other things, on egg surfaces and lines , on space curves and various other topics of differential geometry .

Kubota's name is associated with an interesting theorem of plane Euclidean geometry , which is named after the Japanese mathematician Fujiwara Matsusaburō and him. This theorem, known as the Fujiwara-Kubota Theorem, gives a distinctive property of the circle by stating:

If in the Euclidean plane an oval line has the property that it either has at most two points in common with a congruent line in any position or coincides with it , then it is a circle. ${\displaystyle E}$ ${\displaystyle E^{'}}$ ${\displaystyle E^{'}}$ ${\displaystyle E}$

In 1925 he proved the general n-dimensional case of Cauchy's surface formula .

literature

• Heinrich Behnke , Friedrich Bachmann , Kuno Fladt , Wilhelm Süss (eds.): Fundamentals of mathematics . Volume II. Geometry. Vandenhoeck & Ruprecht , Göttingen 1960, p. 510-529 .
• Siegfried Gottwald , Hans-Joachim Ilgauds and Karl-Heinz Schlote (ed.): Lexicon of important mathematicians . Verlag Harri Deutsch , Thun 1990, ISBN 3-8171-1164-9 , p. 262 .

Web links

• MR1089881
• Web link to the Mathematics Genealogy Project
• Web link to MathSciNet (selection of Kubota's work)

Individual evidence

1. ↑ W. Süss , U. Viet , KH Berger : curves and surfaces. b) Convex figures in: H. Behnke et al .: Fundamentals of Mathematics. Volume II. Geometry. , 1960, pp. 522-523 ff

Japanese name: As is common in Japan, the family name comes before the first name in this article . Thus Kubota is the family name, Tadahiko the first name.