2017/07/10 by Anderson L. A. de Araujo, de Araujo, Anderson L. A., Abílio Lemos +3 · 1 citation
Mathematics · #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #math.CA
paper · pdf · doi:10.48550/arxiv.1707.02664
arxiv created 2017/07/10 · arxiv updated 2017/07/11
Abel equations of the form x'(t)=f(t)x3(t)+g(t)x2(t), t ∈ [-a,a], where a>0 is a constant, f and g are continuous functions, are of interest because of their close relation to planar vector fields. If f and g are odd functions, we prove, in this paper, that the Abel equation has a center at the origin. We also consider a class of polynomial differential equations x = -y+Pn(x,y) and y = x+Qn(x,y), where Pn and Qn are homogeneous polynomials of degree n. Using the results obtained for Abel's equation, we obtain a new subclass of systems having a center at the origin.