A short proof of Halin's grid theorem
An end of an infinite graph is an equivalence class of rays (1-way infinite paths), where two rays are equivalent if no finite set of vertices separates them. An end is thick if there are infinitely many disjoint rays all converging to that end. In the paper there is a short proof of a theorem by Halin, which states that whenever a graph has a thick end, it has a subgraph isomorphic to a subdivision of a hexagonal grid \(H\) whose rays all belong to that end.
scientific article; zbMATH DE number 2139436