be a planar system where and . Furthermore where is a simply connected region of the plane. If there exists a function such that (the divergence of the vector field , ) is always of the same sign but not identically zero then there are no periodic solution in the region of the planar system. In addition, if is an annular region contained in on which the above condition is satisfied then there exists at most one periodic solution in .
|Date of creation||2013-03-22 13:37:09|
|Last modified on||2013-03-22 13:37:09|
|Last modified by||Daume (40)|