**Aleksandr Yakovlevich Khinchin** was a Russian mathematician who contributed to many fields including number theory and probability.

- Khinchin attended the technical high school in Moscow where he became fascinated by mathematics.
- At university in Moscow Khinchin worked with Luzin and others.
- This first paper began a series of publications by Khinchin on properties of functions which are retained after deleting a set of density zero at a given point.
- After graduating in 1916, Khinchin remained at Moscow University undertaking research for his dissertation which would allow him to become a university teacher.
- Around 1922 Khinchin took up new mathematical interests when he began to study the theory of numbers and probability theory.
- In 1927 Khinchin was appointed as a professor at Moscow University and, in the same year, he published Basic laws of probability theory.
- Khinchin left Moscow in 1935 to spend two years at Saratov University but returned to Moscow University in 1937 to continue his role of building the school of probability theory there in partnership with Kolmogorov and others, including in particular their student Gnedenko.
- We shall look at some of Khinchin's major publications and in this way get a feel for the large number of important contributions he made in a remarkably large range of topics.
- Khinchin first published the book Continued Fractions in 1936 with a second edition being published in 1949.
- The third chapter, the longest and most important, contains an account of Khinchin's own contributions to the topic of the metrical theory of Diophantine approximations.
- Another contribution by Khinchin to number theory is the short book Three pearls of number theory which appeared in an English translation in 1952.
- The book Eight lectures on mathematical analysis by Khinchin ran to several editions.
- Khinchin published Mathematical Principles of Statistical Mechanics in 1943.
- Khinchin's book Mathematical Foundations of Information Theory, translated into English from the original Russian in 1957, is important.
- Khinchin generalised some of Shannon's results in this book which was written in an elementary style yet gave a comprehensive account with full details of all the results.
- Among the many honours which Khinchin received for his work was election to the USSR Academy of Sciences in 1939 and the award of a State Prize for scientific achievements in the following year.

Born 19 July 1894, Kondrovo, Kaluzhskaya guberniya, Russia. Died 18 November 1959, Moscow, USSR.

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Origin Russia

**Oâ€™Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive