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CC-center of a class of rigid di?erential systems
Z. Zhou,Y. Yan
Keywords:Uniformly Isochronous Center; Rigid System; Composition Conjecture; CC-Center Center Conditions.
      In this paper, we answer the question: under what conditions a class of rigid di?erential systems have a compositions center (CC-center). We give the su?cient and necessary conditions for these systems to have a center at origin point. At the same time, we give the formula of focal values and the highest order of ?ne focus.