The Non Planar Vertex Deletion of \(C_n \times C_m\)

C.F. X.de Mendonca1, E.F. Xavier2, J. Stolfi3, L. Faria4, C.M. H.de Figueiredo5
1Departamento de Informatica, UEM, Maring4, PR, Brazil.
2Instituto de Computagao, Unicamp, Campinas, SP, Brazil.
3Instituto de Computagao, Unicamp, Campinas, SP, Brazil.
4Departamento de Matematica, FFP-UERJ, So Gongalo, RJ, Brazil.
5Instituto de Matemética and COPPE Sistemas e Computacio, UFRJ, Rio de Janeiro, RJ, Brazil.

Abstract

The non-planar vertex deletion or vertex deletion \(vd(G)\) of a graph \(G = (V, E)\) is the smallest non-negative integer \(k\) such that the removal of \(k\) vertices from \(G\) produces a planar graph. Hence, the maximum planar induced subgraph of \(G\) has precisely \(|V| – vd(G)\) vertices. The problem of computing vertex deletion is in general very hard; it is NP-complete. In this paper, we compute the non-planar vertex deletion for the family of toroidal graphs \(C_n \times C_m\).