Details:
Title  The problem of general centerfocus and bifurcation of limit cycles for a planar system of nine degrees  Author(s)  Claudio Dupre, Yu Liu  Type  Article in Journal  Abstract  Our researches are concerned with a class of planar general equivariant system of nine degrees. By making two appropriate transformations of system and calculating focal values carefully, we obtain the conditions that the infinity and three elementary focuses ( − 1 2 , 0 ) , ( − 1 2 , 1 2 ) , ( − 1 2 , − 1 2 ) become four general centers at the same time. Moreover, 20 limit cycles including 15 small limit cycles from three elementary foci and 5 large limit cycles from the infinity can occur under a certain condition. What is worth mentioning is that similar conclusions are hardly seen in published papers up till now and our work is completely new.  Keywords  General equivariant system, General center, General fine focus, General focal values, Limit cycle  ISSN  03770427 
URL 
http://www.sciencedirect.com/science/article/pii/S0377042708001441 
Language  English  Journal  Journal of Computational and Applied Mathematics  Volume  223  Number  2  Pages  1043  1057  Year  2009  Edition  0  Translation 
No  Refereed 
No 
