Explicit formulas for e-positivity of chromatic quasisymmetric functions

Seung Jin Lee, Sue Kyong Y. Soh

In 1993, Stanley and Stembridge conjectured that a chromatic symmetric function of any $(3+1)$-free poset is $e$-positive. Guay-Paquet reduced the conjecture to $(3+1)$- and $(2+2)…