Opuscula Math. 32, no. 2 (), 357-375
http://dx.doi.org/10.7494/OpMath.2012.32.2.357
Opuscula Mathematica

Planar nonautonomous polynomial equations IV. Nonholomorphic case

Abstract. We give a few sufficient conditions for the existence of periodic solutions of the equation $$\dot{z}=\sum_{j=0}^n a_j(t)z^j-\sum_{k=1}^r c_k(t)\overline{z}^k$$ where $$n \gt r$$ and $$a_j$$'s, $$c_k$$'s are complex valued. We prove the existence of one up to two periodic solutions.
Keywords: periodic orbits, polynomial equations.
Mathematics Subject Classification: 34C25, 34C37.