Lower Subdifferentiability and Integration

Abstract : We consider the question of integration of a multivalued operator $T$, that is the question of finding a function $f $such that $T⊑∂f$. If $∂ $ is the Fenchel–Moreau subdifferential, the above problem has been completely solved by Rockafellar, who introduced cyclic monotonicity as a necessary and sufficient condition. In this article we consider the case where $f$ is quasiconvex and $∂ $ is the lower subdifferential $∂<$. This leads to the introduction of a property that is reminiscent to cyclic monotonicity. We also consider the question of the density of the domains of subdifferential operators.