Title: The Poset Conjecture: results, counterexamples, and open problemsSpeaker: David Wagner Affiliation: University of Waterloo Zoom: Contact Karen Yeats
In 1978, Neggers conjectured that a certain transform of the order polynomial of a partially ordered set (poset) has only real roots.
In the late 1980s, Stanley gave this to me as a thesis project, generalized to labelled posets. For my thesis I proved the conclusion for series-parallel labelled posets and a bit more. Br\"and\'en, and later Stembridge, found counterexamples to the conjecture in general.