Results 31 to 40 of about 1,606 (89)
Homomorphism and sigma polynomials
By establishing a connection between the sigma polynomial and the homomorphism polynomial, many of the proofs for computing the sigma polynmial are simplified, the homomorphism polynomial can be identified for several new classes of graphs, and progress can be made on identifying homomorphism polynomials.
Richard Alan Gillman
wiley +1 more source
Two-distance vertex-distinguishing index of sparse graphs
The two-distance vertex-distinguishing index χd2′(G){\chi }_{d2}^{^{\prime} }\left(G) of graph GG is defined as the smallest integer kk, for which the edges of GG can be properly colored using kk colors.
He Zhengyue, Liang Li, Gao Wei
doaj +1 more source
Homomorphisms and related contractions of graphs
For every homomorphism ϕ of a graph G there exists a contraction θϕ on , the complement of G. Here we study the graph equation . In the course of our work we show that Hadwiger′s Conjecture is true for every self‐complementary graph.
Robert D. Girse, Richard A. Gillman
wiley +1 more source
Burnside Chromatic Polynomials of Group-Invariant Graphs
We introduce the Burnside chromatic polynomial of a graph that is invariant under a group action. This is a generalization of the Q-chromatic function Zaslavsky introduced for gain graphs.
White Jacob A.
doaj +1 more source
Homomorphisms of complete n‐partite graphs
It is shown that for every homomorphism ϕ of a graph G there exists a contraction θϕ on , the complement of G, such that if and only if G is a complete n‐partite graph.
Robert D. Girse
wiley +1 more source
Generalized Ramsey numbers for paths in 2‐chromatic graphs
Chung and Liu have defined the d‐chromatic Ramsey number as follows. Let 1 ≤ d ≤ c and let . Let 1, 2, …, t be the ordered subsets of d colors chosen from c distinct colors. Let G1, G2, …, Gt be graphs. The d‐chromatic Ramsey number denoted by is defined as the least number p such that, if the edges of the complete graph Kp are colored in any fashion ...
R. Meenakshi, P. S. Sundararaghavan
wiley +1 more source
On the structure of a triangle‐free infinite‐chromatic graph of Gyarfas
Gyárfás has recently constructed an elegant new example of a triangle‐free infinite graph G with infinite chromatic number. We analyze its structure by studying the properties of a nested family of subgraphs Gn whose union is G.
Larry Eggan, Frank Harary
wiley +1 more source
DP-coloring is generalized via relaxed coloring and variable degeneracy in [P. Sittitrai and K. Nakprasit, Su cient conditions on planar graphs to have a relaxed DP-3-coloring, Graphs Combin. 35 (2019) 837–845], [K.M. Nakprasit and K.
Sribunhung Sarawute +3 more
doaj +1 more source
Background: Gabapentin reportedly decreases central sensitisation, a disorder associated with chronic pruritus in humans, although this is not well documented in cats. Its combined use with the standard antipruritic therapy for feline atopic skin syndrome (FASS) is not yet described.
Jeanne Morency +10 more
wiley +1 more source
Total Colourings of Direct Product Graphs
A graph is k-total colourable if there is an assignment of k different colours to the vertices and edges of the graph such that no two adjacent nor incident elements receive the same colour.
Janssen, Jeannette, MacKeigan, Kyle
core +1 more source

