Richard Ehrenborg

Abstract:   We completely characterize the factorial functions of Eulerian binomial posets. For Eulerian Sheffer posets with binomial factorial function corresponding to the Boolean algebra, there are three possibilities for the Sheffer factorial function. We end with several poset constructions, all of which yield the same factorial functions as the cubical lattice. This shows that classifying Sheffer posets is a difficult, but interesting question.

Here are some directions to Northeastern University. Lake Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street.