Results 31 to 40 of about 2,394 (219)

ON CHROMATIC UNIQUENESS OF SOME COMPLETE TRIPARTITE GRAPHS

open access: yesUral Mathematical Journal, 2021
Let \(P(G, x)\) be a chromatic polynomial of a graph \(G\). Two graphs \(G\) and \(H\) are called chromatically equivalent iff \(P(G, x) = H(G, x)\). A graph \(G\) is called chromatically unique if \(G\simeq H\) for every \(H\) chromatically equivalent ...
Pavel A. Gein
doaj   +1 more source

The chromatic polynomial of a graph [PDF]

open access: yesPacific Journal of Mathematics, 1985
First, the author summarizes some known results on chromatical polynomials and sketches their proofs. Then he lists the chromatical polynomials of all graphs with fewer than seven vertices.
openaire   +2 more sources

Note on chromatic polynomials of the threshold graphs

open access: yesElectronic Journal of Graph Theory and Applications, 2019
Let G be a threshold graph. In this paper, we give, in first hand, a formula relating the chromatic polynomial of Ḡ (the complement of G) to the chromatic polynomial of G.
Noureddine Chikh, Miloud Mihoubi
doaj   +1 more source

On Weakly Distinguishing Graph Polynomials [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2019
A univariate graph polynomial P(G;X) is weakly distinguishing if for almost all finite graphs G there is a finite graph H with P(G;X)=P(H;X). We show that the clique polynomial and the independence polynomial are weakly distinguishing.
Johann A. Makowsky, Vsevolod Rakita
doaj   +1 more source

A Categorification for the Signed Chromatic Polynomial

open access: yesThe Electronic Journal of Combinatorics, 2022
By coloring a signed graph by signed colors, one obtains the signed chromatic polynomial of the signed graph. For each signed graph we construct graded cohomology groups whose graded Euler characteristic yields the signed chromatic polynomial of the signed graph.
Zhiyun Cheng   +3 more
openaire   +2 more sources

Chromatic polynomials of hypergraphs

open access: yesApplied Mathematics Letters, 2007
The authors investigate the number of \(\lambda\)-colourings of the vertices of a hypergraph \(H\) such that each edge \(e_i\) of \(H\) contains at least \(x_i\) differently coloured vertices for given quantities \(x_1,\dots,x_m\) (one for each edge).
Ewa Drgas-Burchardt, Ewa Lazuka
openaire   +1 more source

Chromatic Polynomials of Simplicial Complexes [PDF]

open access: yesGraphs and Combinatorics, 2015
We consider s-chromatic polynomials of simplicial complexes, higher dimensional analogues of chromatic polynomials for graphs.
Møller, Jesper Michael, Nord, Gesche
openaire   +4 more sources

Approximating the Chromatic Polynomial

open access: yesCoRR, 2016
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 implemented two algorithms that approximate the coefficients of the chromatic polynomial $P(G,x)$, where $P(G,k)$ is ...
Yvonne Kemper, Isabel Beichl
openaire   +2 more sources

Chromatically unique 6-bridge graph theta(a,a,a,b,b,c)

open access: yesElectronic Journal of Graph Theory and Applications, 2016
For a graph $G$, let $P(G,\lambda)$ denote the chromatic polynomial of $G$. Two graphs $G$ and $H$ are chromatically equivalent if they share the same chromatic polynomial. A graph $G$ is chromatically unique if for any graph chromatically equivalent to $
N.S.A. Karim   +2 more
doaj   +1 more source

Coloring Rings in Species [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2014
We present a generalization of the chromatic polynomial, and chromatic symmetric function, arising in the study of combinatorial species. These invariants are defined for modules over lattice rings in species.
Jacob White
doaj   +1 more source

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