2 citations · 5 across the 5 of their papers we have counts for
5 papers
Francis Guthrie's approach to The Four Color Problem
Asbjørn Brændeland
The odd wheel is the only type of 4-critical graph in which one vertex always gets a unique color. This supports Frederic Guthrie's approach to the Four Color Problem.
Split-by-edges trees
Asbjørn Brændeland
A split-by-edges tree of a graph G on n vertices is a binary tree T where the root = V(G), every leaf is an independent set in G, and for every other node N in T with children L an…
Depth-first search in split-by-edges trees
Asbjørn Brændeland
A layerwise search in a split-by-edges tree (as defined by Brændeland, 2015) of agiven graph produces a maximum independent set in exponential time. A depth-first search produces a…
Color fixation and color identity in 4-chromatic graphs
Asbjørn Brændeland
I argue that there is no 4-chromatic planar graph with a joinable pair of color identical vertices, i.e., given a 4-chromatic planar graph G and a pair of vertices {u, v} in G, if…
Color identical pairs in 4-chromatic graphs
Asbjørn Brændeland
I argue that, given vertices u and v in a 4-chromatic graph G, if the color of u equals the color of v in every 4-coloring of G then G has no planar supergraph where u and v are ad…