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Related papers: On Calculating the Chromatic Symmetric Function

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The main result of this paper is the introduction of marked graphs and the marked graph polynomials ($M$-polynomial) associated with them. These polynomials can be defined via a deletion-contraction operation. These polynomials are a…

Combinatorics · Mathematics 2022-02-25 José Aliste-Prieto , Anna de Mier , Rosa Orellana , José Zamora

The Kromatic symmetric function (KSF) $\overline{X}_G$ of a graph $G$ is a $K$-analogue introduced by Crew, Pechenik, and Spirkl in arXiv:2301.02177 of Stanley's chromatic symmetric function (CSF) $X_G$. The KSF is known to distinguish some…

Combinatorics · Mathematics 2025-10-03 Laura Pierson , Soham Samanta

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…

Combinatorics · Mathematics 2020-01-16 Logan Crew , Sophie Spirkl

Let $T$ be an unrooted tree. The \emph{chromatic symmetric function} $X_T$, introduced by Stanley, is a sum of monomial symmetric functions corresponding to proper colorings of $T$. The \emph{subtree polynomial} $S_T$, first considered…

Combinatorics · Mathematics 2011-10-05 Jeremy L. Martin , Matthew Morin , Jennifer D. Wagner

The chromatic symmetric function of a graph is a generalization of the chromatic polynomial. The key motivation for studying the structure of a chromatic symmetric function is to answer positivity conjectures by Stanley in 1995 and Gasharov…

Combinatorics · Mathematics 2014-11-10 Ryan Kaliszewski

A well-known result of Stanley's shows that given a graph $G$ with chromatic symmetric function expanded into the basis of elementary symmetric functions as $X_G = \sum c_{\lambda}e_{\lambda}$, the sum of the coefficients $c_{\lambda}$ for…

Combinatorics · Mathematics 2025-05-16 Logan Crew , Yongxing Zhang

We prove some Schur positivity results for the chromatic symmetric function $X_G$ of a (hyper)graph $G$, using connections to the group algebra of the symmetric group. The first such connection works for (hyper)forests $F$: we describe the…

Combinatorics · Mathematics 2024-10-29 Brendan Pawlowski

We use a well known concept of proper vertex colouring of a graph to introduce the construction of a chromatic completion graph and its related parameter, the chromatic completion number of a graph. We then give the chromatic completion…

General Mathematics · Mathematics 2018-09-06 E. G Mphako-Banda , J. Kok

A new algorithm to obtain the chromatic number of a finite, connected graph is proposed in this paper. The algorithm is based on contraction of non adjacent vertices.

Discrete Mathematics · Computer Science 2019-10-16 Athma. M. Ram , R. Rama

We introduce $H$-chromatic symmetric functions, $X_{G}^{H}$, which use the $H$-coloring of a graph $G$ to define a generalization of Stanley's chromatic symmetric functions. We say two graphs $G_1$ and $G_2$ are $H$-chromatically equivalent…

Combinatorics · Mathematics 2022-05-23 Nancy Mae Eagles , Angèle M. Foley , Alice Huang , Elene Karangozishvili , Annan Yu

We discover new linear relations between the chromatic symmetric functions of certain sequences of graphs and apply these relations to find new families of e-positive unit interval graphs. Motivated by the results of Gebhard and Sagan, we…

Combinatorics · Mathematics 2024-12-24 Farid Aliniaeifard , Victor Wang , Stephanie van Willigenburg

In this paper, we investigate the strength of chromatic symmetric homology as a graph invariant. Chromatic symmetric homology is a lift of the chromatic symmetric function for graphs to a homological setting, and its Frobenius…

Combinatorics · Mathematics 2019-12-02 Alex Chandler , Radmila Sazdanovic , Salvatore Stella , Martha Yip

The orbital bivariate chromatic polynomial, introduced in this article, counts the number of ways to color the vertices of a graph with $\lambda$ colors such that adjacent vertices either receive distinct colors from a set of $\lambda$…

Combinatorics · Mathematics 2025-11-05 Klaus Dohmen , Mandy Lange-Geisler

Stanley asked whether a tree is determined up to isomorphism by its chromatic symmetric function. We approach Stanley's problem by studying the relationship between the chromatic symmetric function and other invariants. First, we prove…

Combinatorics · Mathematics 2024-07-24 José Aliste-Prieto , Jeremy L. Martin , Jennifer D. Wagner , José Zamora

We prove necessary conditions for certain elementary symmetric functions, $e_\lambda$, to appear with nonzero coefficient in Stanley's chromatic symmetric function as well as in the generalization considered by Shareshian and Wachs. We do…

Combinatorics · Mathematics 2024-07-09 Bruce E. Sagan , Foster Tom

We investigate chromatic symmetric functions in the relation to the algebra $\Gamma$ of symmetric functions generated by Schur $Q$-functions. We construct natural bases of $\Gamma$ in terms of chromatic symmetric functions. We also consider…

Combinatorics · Mathematics 2019-07-24 Soojin Cho , JiSun Huh , Sun-Young Nam

Chromatic symmetric functions are well-studied symmetric functions in algebraic combinatorics that generalize the chromatic polynomial and are related to Hessenberg varieties and diagonal harmonics. Motivated by the Stanley--Stembridge…

Combinatorics · Mathematics 2025-02-11 Jacob P. Matherne , Alejandro H. Morales , Jesse Selover

A well-known open problem in graph theory asks whether Stanley's chromatic symmetric function, a generalization of the chromatic polynomial of a graph, distinguishes between any two non-isomorphic trees. Previous work has proven the…

Combinatorics · Mathematics 2020-02-05 Jake Huryn

We compute an explicit $e$-positive formula for the chromatic symmetric function of a lollipop graph, $L_{m,n}$. From here we deduce that there exist countably infinite distinct $e$-positive, and hence Schur-positive, bases of the algebra…

Combinatorics · Mathematics 2018-09-03 Samantha Dahlberg , Stephanie van Willigenburg

Stanley introduced the concept of chromatic symmetric functions of graphs which extends and refines the notion of chromatic polynomials of graphs, and asked whether trees are determined up to isomorphism by their chromatic symmetric…

Combinatorics · Mathematics 2024-02-21 Yuzhenni Wang , Xingxing Yu , Xiao-Dong Zhang