Yuri Anatol'evich Ilyin
Universitetsky prospekt, 28,
198504, Peterhof, St. Petersburg, Russia,
Saint-Petersburg State University,
The Faculty of Mathematics and Mechanics,
Differential Equations Department
In this paper we deal with a periodic system of differential equations which have a solution with incommensurable period. Massera and Kurzeveil found the characteristical property of such a system. Erugin researched in detail the few particular examples. In particular he proved some theorem for 2-dimensional linear system. This paper continues Erugin's investigations. We considered 1- and 2-dimensial cases and proved the few new results. Erugin's theorem for linear systems has been generalized on arbitrary dimension.