Korkin, Aleksandr Nikolaevich
Born Feb. 19 (Mar. 3), 1837, near the village of Shuiskoe in what is now Mezhdurechenskii Raion, Vologda Oblast; died Aug. 19 (Sept. 1), 1908, in St. Petersburg. Russian mathematician.
In 1858, Korkin graduated from the University of St. Petersburg, where he was a student of P. L. Chebyshev. Beginning in 1868 he was a professor at the university (from 1886, professor emeritus). For more than 30 years he was also a professor at the Naval Academy, where he was succeeded in 1900 by his student A. N. Krylov.
Korkin’s principal works were devoted to the integration of partial differential equations and to the theory of numbers. In the latter he was primarily concerned with the theory of quadratic forms and the theory of comparisons. Together with E. I. Zolotarev he succeeded in solving the difficult problem of the exact boundaries of the minimum of positive quadratic forms with four and five variables (1871-77). In the theory of comparisons, Korkin proposed a method of solving binomial comparisons; this method is based on introducting numbers designated by Korkin as “characters.”