National Academy of Sciences of Belarus

IZOBOV Nikolay Alekseevich

IZOBOV Nikolay Alekseevich

Nikolay Alekseevich Izobov (b. 23.01.1940, v. Krasyni, Liozno district, Vitebsk region), mathematician. Academician of the National Academy of Sciences of Belarus (1994, corresponding member since 1980), Doctor of Physico-Mathematical Sciences (1979), Professor (1990).

Research on ordinary differential equations, in particular, on the theory of Lyapunov characteristic exponents and the theory of stability, the linear Konti-Koppel systems, the Emden-Fowler equations and the linear Pfaff systems. A criterion for the stability of Lyapunov exponents of linear systems was obtained, the particular and general non-critical Lyapunov problems on exponential stability in linear approximation were solved, concepts were introduced, properties were studied, and algorithms for calculating exponential, higher-order central, minimal and sigma-exponents of linear differential systems belonging to the main objects of study of the modern theory of indicators; in the freezing method, the attainability of its main estimate is proved, principal differences and general metric properties in the structure of the sets of lower Perron and Lyapunov characteristic indicators of linear systems and their Lebesgue sets are established. The contractibility of the Konti-Koppel sets with increasing parameter is proved and criteria for their openness, as well as left and right limit sets, are obtained. The exponential stability and instability of nonlinear differential systems with linear Konti-Koppel approximations are fully investigated. In the series of works on the classical Emden-Fowler equations, a fairly complete study of their fast-growing unbounded and vanishing Kneser solutions is given. Research on the structure of the characteristic and lower characteristic sets of linear Pfaff systems.

Author of more than 200 scientific papers, including 2 monographs.

State Prize of the Republic of Belarus in 2000 for a series of works "Investigation of the asymptotic properties of differential and discrete systems".

Awarded with the Order of Francisk Skaryna (2000).

Major papers:

  1. Линейные системы обыкновенных дифференциальных уравнений // Математический анализ. Итоги науки и техники. 1974. Т.12.
  2. О задаче Конти для пересечений множеств линейных систем // Дифференциальные уравнения. 1990. Т.26, №8.
  3. Исследования в Беларуси по теории характеристических показателей Ляпунова и ее приложениям // Там же. 1993. Т.29, №12.
  4. Введение в теорию показателей Ляпунова. Мн.: БГУ, 2006.