A combinatorial formula for the Schur coefficients of chromatic symmetric functions

Autor: David G. L. Wang, Monica M. Y. Wang
Rok vydání: 2020
Předmět:
Zdroj: Discrete Applied Mathematics. 285:621-630
ISSN: 0166-218X
Popis: We provide a formula for every Schur coefficient in the chromatic symmetric function of a graph in terms of special rim hook tabloids. This formula is useful in confirming the non-Schur positivity of the chromatic symmetric function of a graph, especially when Stanley’s stable partition method does not work. As applications, we completely characterize Schur positive complete tripartite graphs. We show that any squid graph obtained by attaching n pendent edges to a common vertex on the cycle C m is not Schur positive if m ≠ 2 n − 1 , and that any pineapple graph obtained by attaching m pendent edges to a common vertex on the complete graph K n is not Schur positive if n ≤ 2 m − 2 .
Databáze: OpenAIRE