English
Related papers

Related papers: A power sum expansion for the Kromatic symmetric f…

200 papers

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 investigate the problem of when a chromatic quasisymmetric function (CQF) $X_G(x;q)$ of a graph $G$ is in fact symmetric. We first prove the remarkable fact that if a product of two quasisymmetric functions $f$ and $g$ in countably…

Combinatorics · Mathematics 2025-08-04 Maria Gillespie , Joseph Pappe , Kyle Salois

The chromatic sum $\Sigma(G)$ of a graph $G$ is the smallest sum of colors among of proper coloring with the natural number. In this paper, we introduce a necessary condition for the existence of graph homomorphisms. Also, we present…

Combinatorics · Mathematics 2009-01-24 Meysam Alishahi , Ali Taherkhani

We define a q-chromatic function on graphs, list some of its properties and provide some formulas in the class of general chordal graphs. Then we relate the q-chromatic function to the colored Jones function of knots. This leads to a…

Combinatorics · Mathematics 2007-05-23 Martin Loebl

Chromatic polynomials are important objects in graph theory and statistical physics, but as a result of computational difficulties, their study is limited to graphs that are small, highly structured, or very sparse. We have devised and…

Discrete Mathematics · Computer Science 2016-08-18 Yvonne Kemper , Isabel Beichl

In this paper, we introduce the \emph{$\alpha$-chromatic symmetric functions} $\chi^{(\alpha)}_\pi[X;q]$, extending Shareshian and Wachs' chromatic symmetric functions with an additional real parameter $\alpha$. We present positive…

Combinatorics · Mathematics 2025-04-21 Jim Haglund , Jaeseong Oh , Meesue Yoo

The chromatic number $\chi(G)$ of a graph $G$ is defined as the minimum number of colours required for a vertex colouring where no two adjacent vertices are coloured the same. The chromatic number of the dense random graph $G \sim G(n,p)$…

Combinatorics · Mathematics 2021-03-29 Annika Heckel

Let $\mathcal{C} = \{c_1,c_2, c_3, \ldots,c_k\}$ be a certain type of proper $k$-colouring of a given graph $G$ and $\theta(c_i)$ denote the number of times a particular colour $c_i$ is assigned to the vertices of $G$. Then, the colouring…

General Mathematics · Mathematics 2016-06-02 N. K. Sudev , K. P. Chithra , Johan Kok

This paper investigates methods for calculating the chromatic symmetric function (CSF) of a graph in chromatic-bases and the $m_\lambda$-basis. Our key contributions include a novel approach for calculating the CSF in chromatic-bases…

Combinatorics · Mathematics 2025-02-25 Nima Amoei Mobaraki , Yasaman Gerivani , Sina Ghasemi Nezhad

In this note we classify when a skew Schur function is a positive linear combination of power sum symmetric functions. We then use this to determine precisely when any scalar multiple of a skew Schur function is the chromatic symmetric…

Combinatorics · Mathematics 2018-09-03 Soojin Cho , Stephanie van Willigenburg

In [J. Combin. Theory Ser. B 161 (2023), 109--119], the authors showed that the list-color function $P_l(G,k)$ of any simple graph $G$ of size $m$ coincides with its chromatic polynomial $P(G,k)$ for all integers $k\ge m-1$. In this…

Combinatorics · Mathematics 2024-12-11 Fengming Dong , Meiqiao Zhang

We give a new interpretation of the chromatic polynomial of a simple graph G in terms of the Kac-Moody Lie algebra with Dynkin diagram G. We show that the chromatic polynomial is essentially the q-Kostant partition function of this Lie…

Representation Theory · Mathematics 2015-05-22 R. Venkatesh , Sankaran Viswanath

Asymptotic expansions of Gaussian integrals may often be interpreted as generating functions for certain combinatorial objects (graphs with additional data). In this article we discuss a general approach to all such cases using colored…

Combinatorics · Mathematics 2010-05-18 I. V. Artamkin

We study the $H$-chromatic symmetric functions $X_G^H$ (introduced in (arXiv:2011.06063) as a generalization of the chromatic symmetric function (CSF) $X_G$), which track homomorphisms from the graph $G$ to the graph $H$. We focus first on…

Combinatorics · Mathematics 2025-11-13 Shao Yuan Lin , Laura Pierson

A fractional colouring of a graph $G$ is a function that assigns a non-negative real value to all possible colour-classes of $G$ containing any vertex of $G$, such that the sum of these values is at least one for each vertex. The fractional…

Combinatorics · Mathematics 2022-12-27 John Baptist Gauci , Jean Paul Zerafa

By a graph we mean a finite undirected graph having multiple edges but no loops. Given a graph property $\mathcal{P}$, a $\mathcal{P}$-coloring of a graph $G$ with color set $C$ is a mapping $\f:V(G)\to C$ such that for each color $c\in C$…

Combinatorics · Mathematics 2021-08-30 Alexandr V. Kostochka , Thomas Schweser , Michael Stiebitz

Chromatic quasisymmetric functions of labeled graphs were defined by Shareshian and Wachs as a refinement of Stanley's chromatic symmetric functions. In this extended abstract, we consider an extension of their definition from labeled…

Combinatorics · Mathematics 2017-04-17 Brittney Ellzey

We define a new type of vertex coloring which generalizes vertex coloring in graphs, hypergraphs, and simplicial complexes. This coloring also generalizes oriented coloring, acyclic coloring, and star coloring. There is an associated…

Combinatorics · Mathematics 2020-01-22 John Machacek

The quasisymmetic Macdonald polynomials $G_{\gamma}(X; q, t)$ were recently introduced by the first and second authors with Haglund, Mason, and Williams in [3] to refine the symmetric Macdonald polynomials $P_{\lambda}(X; q, t)$ with the…

Combinatorics · Mathematics 2020-11-02 Sylvie Corteel , Olya Mandelshtam , Austin Roberts

DP-coloring (also called correspondence coloring) is a generalization of list coloring that has been widely studied in recent years after its introduction by Dvo\v{r}\'{a}k and Postle in 2015. As the analogue of the chromatic polynomial…

‹ Prev 1 3 4 5 6 7 10 Next ›