Results 31 to 40 of about 1,406 (208)

Chromatic symmetric functions in noncommuting variables revisited [PDF]

open access: yesAdvances in Applied Mathematics, 2020
23 pages, final version to appear Adv.
Samantha Dahlberg   +1 more
openaire   +3 more sources

Positivity of chromatic symmetric functions associated with Hessenberg functions of bounce number 3

open access: yes, 2022
We give a proof of the Stanley-Stembridge conjecture on chromatic symmetric functions for the class of all unit interval graphs with independence number 3.
Cho, Soojin, Jaehyun Hong
core   +1 more source

A deletion–contraction relation for the chromatic symmetric function

open access: yesEuropean Journal of Combinatorics, 2020
We extend the definition of the chromatic symmetric function $X_G$ to include graphs $G$ with a vertex-weight function $w : V(G) \rightarrow \mathbb{N}$. We show how this provides the chromatic symmetric function with a natural deletion-contraction relation analogous to that of the chromatic polynomial.
Logan Crew, Sophie Spirkl
openaire   +4 more sources

A Two Parameter Chromatic Symmetric Function [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2007
We introduce and develop a two-parameter chromatic symmetric function for a simple graph $G$ over the field of rational functions in $q$ and $t,\,{\Bbb Q}(q,t)$. We derive its expansion in terms of the monomial symmetric functions, $m_{\lambda}$, and present various correlation properties which exist between the two-parameter chromatic symmetric ...
openaire   +2 more sources

A Quasisymmetric Function Generalization of the Chromatic Symmetric Function [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2011
The chromatic symmetric function $X_G$ of a graph $G$ was introduced by Stanley. In this paper we introduce a quasisymmetric generalization $X^k_G$ called the $k$-chromatic quasisymmetric function of $G$ and show that it is positive in the fundamental basis for the quasisymmetric functions.
openaire   +3 more sources

Extended chromatic symmetric functions and equality of ribbon Schur functions [PDF]

open access: yesAdvances in Applied Mathematics, 2021
Final version to appear Adv.
Farid Aliniaeifard   +2 more
openaire   +2 more sources

Chromatic classical symmetric functions [PDF]

open access: yesJournal of Combinatorics, 2018
8 pages, minor adjustments to match final version to appear in J ...
Cho, Soojin, van Willigenburg, Stephanie
openaire   +2 more sources

The equivalence of two graph polynomials and a symmetric function

open access: yes, 2009
The U-polynomial, the polychromate and the symmetric function generalization of the Tutte polynomial due to Stanley are known to be equivalent in the sense that the coefficients of any one of them can be obtained as a function of the coefficients of any ...
Noble, SD   +5 more
core   +1 more source

Chromatic Symmetric Functions of Hypertrees

open access: yesThe Electronic Journal of Combinatorics, 2017
The chromatic symmetric function $X_H$ of a hypergraph $H$ is the sum of all monomials corresponding to proper colorings of $H$. When $H$ is an ordinary graph, it is known that $X_H$ is positive in the fundamental quasisymmetric functions $F_S$, but this is not the case for general hypergraphs.
openaire   +3 more sources

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