Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
We present some spectral conditions in order to describe the phase portrait of a planar vector field, in a neighborhood of infinity. Suppose that X is a planar vector field whose linearization outside some compact set is Hurwitz: it admits to the origin as a linear hyperbolic attractor. Then by adding to X a constant vector, one obtains that the infinity is either an attractor or a repellor.