On the Surjectivity Properties of Perturbations of Maximal Monotone Operators in Non-Reflexive Banach Spaces

We are concerned with surjectivity of perturbations of maximal monotone operators in non-reflexive Banach spaces. While in a reflexive setting, a classical surjectivity result due to Rockafellar gives a necessary and sufficient condition to maximal monotonicity, in a non-reflexive space we characterize maximality using an "enlarged" version of the duality mapping, introduced previously by Gossez.