The planarity auxiliary graph of a graph is given by Yanpei Liu. This paper generalizes the planarity auxiliary graph to projective planar. The projective planarity of signed graphs is characterized as follows: the corresponding auxiliary graph of a given signed graph is balanced iff the graph is projective planar.
HAO Rongxia
, LIU Yanpei. , {{custom_author.name_en}}.
Auxiliary Graphs of Projective Planar Signed Graphs. Journal of Systems Science and Mathematical Sciences, 2010, 30(9): 1251-1258 https://doi.org/10.12341/jssms09263