Abstract
A class of cubic graphs is introduced for which the genus is a nonadditive function of the genus of subgraphs. This provides a small (28 node) counterexample to Duke’s conjecture concerning the relation of the Betti number to the genus of a graph.
Similar content being viewed by others
References
J. Battle et al.,Additivity of the genus of a graph, Bull. Amer. Math. Soc.68 (1963), 565–568.
R.A. Duke,The genus, regional number, and the Betti number of a graph, Canad. J. Math.18, 817–822.
I. N. Kagno,The mapping of graphs on surfaces, J. Math. Phys.16 (1937) 46–75.
M. Milgram,Irreducible graphs, J. Combinatorial Theory (B)12 (1972), 6–31.
M. Milgram,Irreducible graphs—Part 2, J. Combinatorial Theory (B)14 (1973), 7–45.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Milgram, M. The nonadditivity of the genus. Israel J. Math. 19, 201–207 (1974). https://doi.org/10.1007/BF02757712
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02757712