2010/12/28 by Aigner-Horev, Elad, Krakovski, Roi
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1012.5793
We provide a short proof that a 5-connected nonplanar apex graph contains a subdivided K5 or a K-4 (= K4 with a single edge removed) as a subgraph. Together with a recent result of Ma and Yu that \sl every nonplanar 5-connected graph containing K-4 as a subgraph has a subdivided K5; this settles the Kelmans-Seymour conjecture for apex graphs.