Reducing the Chromatic Number by Vertex or Edge Deletions

Distinguishing Edge Chromatic Number

An adjacent vertex distinguishing edge-coloring or an avd-coloring of a simple graph G is a proper edge-coloring of G such that no pair of adjacent vertices meets the same set of colors. We prove that every graph with maximum degree ∆ and with no isolated edges has an avd-coloring with at most ∆ + 300 colors, provided that ∆ > 1020. AMS Subject Classification: 05C15

Delta+300 is a bound on the adjacent vertex distinguishing edge chromatic number

Edge-face chromatic number and edge chromatic number of simple plane graphs

Given a simple plane graph G, an edge-face k-coloring of G is a function : E(G) [ F (G) ! f1, . . . ,kg such that, for any two adjacent or incident elements a, b 2 E(G) [ F (G), (a) 61⁄4 (b). Let e(G), ef(G), and (G) denote the edge chromatic number, the edge-face chromatic number, and the maximum degree of G, respectively. In this paper, we prove that ef(G) 1⁄4 e(G) 1⁄4 (G) for any 2-connected...

The b-chromatic number and f-chromatic vertex number of regular graphs

The b-chromatic number of a graph G, denoted by b(G), is the largest positive integer k such that there exists a proper coloring for G with k colors in which every color class contains at least one vertex adjacent to some vertex in each of the other color classes, such a vertex is called a dominant vertex. The f -chromatic vertex number of a d-regular graph G, denoted by f(G), is the maximum nu...

The locating-chromatic number for Halin graphs

Let G be a connected graph. Let f be a proper k -coloring of G and Π = (R_1, R_2, . . . , R_k) bean ordered partition of V (G) into color classes. For any vertex v of G, define the color code c_Π(v) of v with respect to Π to be a k -tuple (d(v, R_1), d(v, R_2), . . . , d(v, R_k)), where d(v, R_i) is the min{d(v, x)|x ∈ R_i}. If distinct vertices have distinct color codes, then we call f a locat...