LIST INJECTIVE COLORING OF PLANAR GRAPHS WITH GIRTH g ≥ 5

Abstract

An injective-k coloring of a graph G is a mapping cV(G) → {1, 2, …, k}, such that c(u) ≠ c(v) for each u, v ∈ V(G), whenever u, v have a common neighbor in G. If G has an injective-k coloring, then we call that G is injective-k colorable. Call χi(G) = min {k | G is injective-k colorable} is the injective chromatic number of G. Assign each vertex v ∈ V(G) a coloring set L(v), then L = {L(v) | v ∈ V(G)} is said to be a color list of G. Let L be a color list of G, if G has an injective coloring c such that c(v) ∈ L(v), ∀v ∈ V(G), then we call c an injective L-coloring of G. If for any color list L, such that |L(v)| ≥ k, G has an injective L-coloring, then G is said to be injective k-choosable. Call [Formula: see text] is injective k-choosable} is the injective chromatic number of G. So far, for the plane graph G of girth g(G) ≥ 5 and maximum degree Δ(G) ≥ 8, the best result of injective chromatic number is χi(G) ≤ Δ + 8. In this paper, for the plane graph G, we proved that [Formula: see text] if girth g(G) ≥ 5 and maximum degree Δ(G) ≥ 8.