Per Alexandersson: P-partitions and p-positivity

Abstract

We study certain quasisymmetric functions given by posets, and prove that these are positive in a quasisymmetric analogue of the power-sum symmetric functions.This result implies power-sum positivity results for many families of symmetric functions, such as chromatic quasisymmetric functions, unicellular LLT polynomials and so on.

This is joint work with Robin Sulzgruber.