Characterizing 2-crossing-critical graphs
Abstract
It is very well-known that there are precisely two minimal non-planar graphs: and (degree 2 vertices being irrelevant in this context). In the language of crossing numbers, these are the only 1-crossing-critical graphs: they each have crossing number at least one, and every proper subgraph has crossing number less than one. In 1987, Kochol exhibited an infinite family of 3-connected, simple 2-crossing-critical graphs. In this work, we: (i) determine all the 3-connected 2-crossing-critical graphs that contain a subdivision of the M\"obius Ladder ; (ii) show how to obtain all the not 3-connected 2-crossing-critical graphs from the 3-connected ones; (iii) show that there are only finitely many 3-connected 2-crossing-critical graphs not containing a subdivision of ; and (iv) determine all the 3-connected 2-crossing-critical graphs that do not contain a subdivision of .
Keywords
Cite
@article{arxiv.1312.3712,
title = {Characterizing 2-crossing-critical graphs},
author = {Drago Bokal and Bogdan Oporowski and R. Bruce Richter and Gelasio Salazar},
journal= {arXiv preprint arXiv:1312.3712},
year = {2013}
}
Comments
176 pages, 28 figures