Buzzi, Claudio A.Llibre, JaumeMedrado, Joao C.Torregrosa, Joan2014-05-202014-05-202009-01-01Dynamical Systems-an International Journal. Abingdon: Taylor & Francis Ltd, v. 24, n. 1, p. 123-137, 2009.1468-9367http://hdl.handle.net/11449/40908For every positive integer N >= 2 we consider the linear differential centre (x) over dot = Ax in R-4 with eigenvalues +/- i and +/- Ni. We perturb this linear centre inside the class of all polynomial differential systems of the form linear plus a homogeneous nonlinearity of degree N, i.e. (x) over dot Ax + epsilon F(x) where every component of F(x) is a linear polynomial plus a homogeneous polynomial of degree N. Then if the displacement function of order epsilon of the perturbed system is not identically zero, we study the maximal number of limit cycles that can bifurcate from the periodic orbits of the linear differential centre.123-137engperiodic orbitslimit cyclespolynomial vector fieldsperturbationresonance 1:NArtigo10.1080/14689360802534492WOS:000263644000009Acesso restrito66828677607174450000-0003-2037-8417