Abram Samoilowitsch Besikowitsch

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Abram Samoilowitsch Besikowitsch ( Russian Абрам Самойлович Безикович , in English mostly quoted as AS Besicovitch ; born January 24, 1891 in Berdyansk , Taurian governorate ; † November 2, 1970 in Cambridge , England ), was a British mathematician of Caraic - Russian origin.

Life

Besikowitsch was born the fourth of six children to parents who belonged to the Jewish religious community of the Karaites . He studied mathematics in Saint Petersburg with Andrei A. Markow , where he graduated in 1912. He married in 1916; his wife was a converted Jew and was not allowed to marry a Karaite, which is why he converted to the Orthodox Church for the marriage license. In the midst of the turmoil of the revolution, Besikowitsch became professor in Perm in 1917 and in St. Petersburg in 1919. In 1924, he went without his wife (the couple divorced in 1928, the same year he married a Russian woman, again he from Perm knew) with a Rockefeller Fellowship to Copenhagen to Harald Bohr , under whose influence he his field of probability theory to almost periodic functions changed. In 1925 he visited Godfrey Harold Hardy in Oxford , who gave him a job in Liverpool. In 1927 he went to Cambridge , where he succeeded John Edensor Littlewood as Rouse Ball Professor in 1950 . In 1958 he retired , held guest lectures at various US universities until 1966 and then returned to Trinity College in Cambridge .

Besikowitsch is best known for developing the theory of fractals , that is, sets of non-integer dimensions ( Hausdorff-Besikowitsch dimension , introduced by Felix Hausdorff in 1918, expanded by Besikowitsch around 1930). In 1925 he solved the Kakeya needle problem by proving that the area covered by a 360-degree stretch of length 1 can be arbitrarily small. Even before that (1919) he had shown that Besikowitsch sets (which contain a unit length in any orientation) can have any small measure. A lecture by Besikowitsch on the Kakeya needle problem was filmed by the Mathematical Association of America in the 1960s.

Further areas of work were real analysis, measure theory and the theory of almost periodic functions. Often he went on surprising, original paths.

Besikowitsch was accepted as a member (" Fellow ") in the Royal Society in 1934, which in 1952 awarded him the New Year's Eve Medal . He received the De Morgan Medal of the London Mathematical Society in 1950 .

The asteroid (16953) Besicovitch was named after him.

Quotes

  • The reputation of a mathematician is based on the number of erroneous evidence he gave , A mathematician's reputation rests on the number of bad proofs he has given

Fonts

  • Almost periodic functions , Dover 1954
  • The Kakeya Problem , American Mathematical Monthly, Volume 70, 1963, p. 697

Web links

Individual evidence

  1. JC Burkill : Abram Samoilovitch Besicovitch. 1891-1970 . Biographical Memoirs of Fellows of the Royal Society. Vol. 17, (Nov., 1971), pp. 1-16, JSTOR 769699
  2. Named after the English mathematician WW Rouse Ball
  3. Named after the Japanese mathematician Sōichi Kakeya
  4. ^ Entry in the archives of the Royal Society .
  5. Besicovitch, quoted in John Edensor Littlewood , A mathematician's miscellany , Methuen 1953, p. 42. What is meant is that pioneering work is often flawed at first, or in Littlewood's words Pioneer work is clumsy