Center problem for several differential equations via Cherkas' method

[摘要] Cherkas' method characterizes centers for analytic Lienard differential equations. We extend his method to degenerate Lienard differential equations and we apply this extension to solve the center problem for several families of polynomial differential equations. In particular, we give all centers for some differential equations given by a vector field which is the sum of two quasi-homogeneous ones. (C) 1998 Academic Press.

[发布日期] 1998-12-15