Computing Center Conditions for Non-analytic Vector Fields with Constant Angular Speed

We investigate the planar quasi-septic non-analytic systems which have a center-focus equilibrium at the origin and whose angular speed is constant. The system could be changed into an analytic system by two transformations, with the help of computer algebra system MATHEMATICA, the conditions of uniform isochronous center are obtained.

• Li Feng

• Non-analytic
• center–focus problem
• Lyapunov constant
• uniform isochronous center.

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