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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

Stanley's theory of $(P,\omega)$-partitions is a standard tool in combinatorics. It can be extended to allow for the presence of a restriction, that is a given maximal value for partitions at each vertex of the poset, as was shown by Assaf…

Combinatorics · Mathematics 2023-03-17 Philippe Nadeau , Vasu Tewari

Motivated by Dohmen-P\"onitz-Tittmann's bivariate chromatic polynomial $\chi_G(x,y)$, which counts all $x$-colorings of a graph $G$ such that adjacent vertices get different colors if they are $\le y$, we introduce a bivarate version of…

Combinatorics · Mathematics 2021-12-21 Matthias Beck , Maryam Farahmand , Gina Karunaratne , Sandra Zuniga Ruiz

For each indifference graph, there is an associated regular semisimple Hessenberg variety, whose cohomology recovers the chromatic symmetric function of the graph. The decomposition theorem applied to the forgetful map from the regular…

Algebraic Geometry · Mathematics 2023-04-24 Alex Abreu , Antonio Nigro

Stanley defined the chromatic symmetric function of a graph, and Shareshian and Wachs introduced a refinement, namely the chromatic quasisymmetric function of a labeled graph. In this paper, we define the chromatic quasisymmetric function…

Combinatorics · Mathematics 2017-09-07 Brittney Ellzey

We prove that the coefficient of the star $\mathfrak{st}_{21^{n-2}}$ in the chromatic symmetric function $X_G$ determines whether a connected graph $G$ is $2$-connected. We also prove new linear relations on other star coefficients of…

Combinatorics · Mathematics 2026-01-21 Rosa Orellana , Foster Tom

The representation is essentially the same as that given by J.P.Nagle in J. Comb. Theory (B), 1971, 10:1, 42--59. The distinction is in the definition of the weighting function via the number of flows. This new definition allows one to…

Combinatorics · Mathematics 2009-03-09 Yu. V. Matiyasevich

We study the polynomial approximation of symmetric multivariate functions and of multi-set functions. Specifically, we consider $f(x_1, \dots, x_N)$, where $x_i \in \mathbb{R}^d$, and $f$ is invariant under permutations of its $N$…

Numerical Analysis · Mathematics 2023-02-06 Markus Bachmayr , Geneviève Dusson , Christoph Ortner , Jack Thomas

The theory of symmetric functions has been extended to the case where each variable is paired with an anticommuting one. The resulting expressions, dubbed superpolynomials, provide the natural N=1 supersymmetric version of the classical…

Mathematical Physics · Physics 2017-05-02 L. Alarie-Vézina , L. Lapointe , P. Mathieu

Richard P. Stanley defined the chromatic symmetric function of a simple graph and has conjectured that every tree is determined by its chromatic symmetric function. Recently, Takahiro Hasebe and the author proved that the order…

Combinatorics · Mathematics 2018-07-23 Shuhei Tsujie

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

We explore several generalizations of Whitney's theorem -- a classical formula for the chromatic polynomial of a graph. Following Stanley, we replace the chromatic polynomial by the chromatic symmetric function. Following Dohmen and Trinks,…

Combinatorics · Mathematics 2023-05-08 Darij Grinberg

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

This paper has two main parts. First, we consider the Tutte symmetric function $XB$, a generalization of the chromatic symmetric function. We introduce a vertex-weighted version of $XB$ and show that this function admits a…

Combinatorics · Mathematics 2021-10-04 José Aliste-Prieto , Logan Crew , Sophie Spirkl , José Zamora

Stanley in his paper [Stanley, Richard P.: Acyclic orientations of graphs In: Discrete Mathematics 5 (1973), Nr. 2, S. 171-178.] provided interpretations of the chromatic polynomial when it is substituted with negative integers. Greene and…

Combinatorics · Mathematics 2019-03-19 Bishal Deb

The $e$-positivity conjecture and the $e$-unimodality conjecture of chromatic quasisymmetric functions are proved for some classes of natural unit interval orders. Recently, J. Shareshian and M. Wachs introduced chromatic quasisymmetric…

Combinatorics · Mathematics 2017-11-28 Soojin Cho , JiSun Huh

Skewing operators play a central role in the symmetric function theory because of the importance of the product structure of the symmetric function space. The theory of noncommutative symmetric functions is a useful tool for studying…

Combinatorics · Mathematics 2023-05-16 Byung-Hak Hwang

Sazdanovic and Yip defined a categorification of Stanley's chromatic function called the chromatic symmetric homology. In this paper we prove that (as conjectured by Chandler, Sazdanovic, Stella and Yip), if a graph $G$ is non-planar, then…

Combinatorics · Mathematics 2023-07-19 Azzurra Ciliberti , Luca Moci

In 1995 Stanley introduced the chromatic symmetric function $X_G$ of a graph $G$, whose $e$-positivity and Schur-positivity has been of large interest. In this paper we study the relative $e$-positivity and Schur-positivity between…

Combinatorics · Mathematics 2020-03-16 Samantha Dahlberg , Adrian She , Stephanie van Willigenburg

We construct a generalization of the theory of symmetric functions involving functions of commuting and anticommuting (Grassmannian) variables. These new functions, called symmetric functions in superspace, are invariant under the diagonal…

Combinatorics · Mathematics 2007-05-23 P. Desrosiers , L. Lapointe , P. Mathieu