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Chromatic polynomials have been studied extensively, giving us results such as the Fundamental Reduction Theorem and closed formulas for the chromatic polynomials of common classes of graphs. Though, none of those extend to the context of…

Combinatorics · Mathematics 2016-10-20 Pedro M. Recuero

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

Stanley associated with a graph G a symmetric function X_G which reduces to G's chromatic polynomial under a certain specialization of variables. He then proved various theorems generalizing results about the chromatic polynomial, as well…

Combinatorics · Mathematics 2007-05-23 David D. Gebhard , Bruce E. Sagan

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

George Birkhoff proved in 1912 that the number of proper colorings of a finite graph G with n colors is a polynomial in n, called the chromatic polynomial of G. Read conjectured in 1968 that for any graph G, the sequence of absolute values…

Combinatorics · Mathematics 2017-06-05 Matthew Baker

Whitney's 2-Isomorphism Theorem characterises when two graphs have isomorphic cycle matroids. We present an analogue of this theorem for graphs embedded in surfaces by characterising when two graphs in surface have isomorphic…

Combinatorics · Mathematics 2019-10-11 Iain Moffatt , Jaeseong Oh

Spectral characterization of graphs is an important topic in spectral graph theory, which has received a lot of attention from researchers in recent years. It is generally very hard to show a given graph to be determined by its spectrum.…

Combinatorics · Mathematics 2021-08-03 Lihong Qiu , Wei Wang , Wei Wang , Hao Zhang

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

In this paper, we consider multivariate hyperedge elimination polynomials and multivariate chromatic polynomials for hypergraphs. The first set of polynomials is defined in terms of a deletion-contraction-extraction recurrence, previously…

Combinatorics · Mathematics 2010-12-16 Jacob A White

In this paper we consider the following three coloring concepts for digraphs. First of all, the generalized coloring concept, in which the same colored vertices of a digraph induce a subdigraph that satisfies a given digraph property.…

Combinatorics · Mathematics 2025-09-23 Lucas Picasarri-Arrieta , Michael Stiebitz

We give an especially simple proof of a theorem in graph theory that forms the key part of the solution to a problem in commutative algebra, on how to characterize the integral closure of a polynomial ring generated by quadratic monomials.

Commutative Algebra · Mathematics 2011-06-09 Peter M. Johnson

We prove that the coindex of the box complex $\mathrm{B}(H)$ of a graph $H$ can be measured by the generalised Mycielski graphs which admit a homomorphism to it. As a consequence, we exhibit for every graph $H$ a system of linear equations…

Combinatorics · Mathematics 2016-01-19 Gord Simons , Claude Tardif , David Wehlau

We focus on two specific generalizations of the chromatic symmetric function: one involving universal graphs and the other concerning vertex-weighted graphs. In this paper, we introduce a unified generalization that incorporates both…

Combinatorics · Mathematics 2025-04-01 Yosuke Sato

Stanley has studied a symmetric function generalization X_G of the chromatic polynomial of a graph G. The innocent-looking Stanley-Stembridge Poset Chain Conjecture states that the expansion of X_G in terms of elementary symmetric functions…

Combinatorics · Mathematics 2007-05-23 Timothy Y. Chow

Recently, M.\ Ab\'ert and T.\ Hubai studied the following problem. The chromatic measure of a finite simple graph is defined to be the uniform distribution on its chromatic roots. Ab\'ert and Hubai proved that for a Benjamini-Schramm…

Combinatorics · Mathematics 2015-12-10 Péter Csikvári , Péter E. Frenkel

We consider a graph polynomial \xi(G;x,y,z) introduced by Averbouch, Godlin, and Makowsky (2007). This graph polynomial simultaneously generalizes the Tutte polynomial as well as a bivariate chromatic polynomial defined by Dohmen, Poenitz…

Combinatorics · Mathematics 2008-01-11 Christian Hoffmann

We establish a connection between root multiplicities for Borcherds-Kac-Moody algebras and graph coloring. We show that the generalized chromatic polynomial of the graph associated to a given Borcherds algebra can be used to give a closed…

Combinatorics · Mathematics 2018-07-11 G. Arunkumar , Deniz Kus , R. Venkatesh

Let $G=(V,E)$ be a simple graph with $V=\{1,2,\cdots,n\}$ and $\chi(G,x)$ be its chromatic polynomial. For an ordering $\pi=(v_1,v_2,\cdots,v_n)$ of elements of $V$, let $\delta_G(\pi)$ be the number of $i$'s, where $1\le i\le n-1$, with…

Combinatorics · Mathematics 2019-09-06 Fengming Dong

We introduce ideas that complement the many known connections between polymatroids and graph coloring. Given a hypergraph that satisfies certain conditions, we construct polymatroids, given as rank functions, that can be written as sums of…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin , Carolyn Chun

Let $G$ be a simple graph and let $\mathcal{L}(G)$ be the free partially commutative Lie algebra associated to $G$. In this paper, using heaps of pieces, we prove an expression for the generalized $\textbf k$-chromatic polynomial of $G$ in…

Combinatorics · Mathematics 2019-07-23 G Arunkumar