RANGE OF SEMILINEAR OPERATORS FOR SYSTEMS AT RESONANCE

PABLO AMSTER; MARIEL PAULA KUNA

ELECTRONIC JOURNAL OF DIFFERENTIAL EQUATIONS

TEXAS STATE UNIVERSITY-SAN MARCOS

Año: 2012 p. 1 - 13

1072-6691

For a vector function we consider the system where is a function. We are interested in finding all possible T-periodic forcing terms p(t) for which there is at least one solution. In other words, we examine the range of the semilinear operator given by , where Writing , where , we present several results concerning the topological structure of the set