On generalized Wilf conjectures

Abstract

We investigate complement-finite submonoids of the monoid of nonnegative integer points of a unipotent linear algebraic group $G$. These monoids are in general noncommutative but they specialize to the generalized numerical monoids of Cisto et al.. We show that every unipotent numerical monoid has a unique finite minimal generating set. We propose a generalization of the Wilf conjecture in our setting. We contrast our Wilf conjecture against the generalized Wilf conjecture. Then we isolate two new families of unipotent numerical monoids called the thick and the thin unipotent numerical monoids. We prove that our Wilf conjecture holds for every thick (commutative) unipotent numerical monoid. Under additional assumptions on the conductors, we prove that our Wilf conjecture holds for every thin (commutative) unipotent numerical monoid.