On the period function of x+f(x)x′2+g(x)=0

JOURNAL OF DIFFERENTIAL EQUATIONS

卷:196

Article

Sabatini, M

关键词: center;    period function;    monotonicity;    polynomial systems;   

DOI  :  10.1016/S0022-0396(03)00067-6

来源: Elsevier

【 摘 要 】

We study the period function T of a center O of the title's equation. A sufficient condition for the monotonicity of T, or for the isochronicity of O, is given. Such a condition is also necessary, when f and g are odd and analytic. In this case a characterization of isochronous centers is given. Some classes of plane systems equivalent to such equation are considered, including some Kukles' systems. (C) 2003 Elsevier Science (USA). All rights reserved.

【 授权许可】

Free