Title of article :
On list vertex 2-arboricity of toroidal graphs without cycles of specific length
Author/Authors :
Zhang ، H. - Huaiyin Normal University
Abstract :
The vertex arboricity ρ(G) of a graph G is the minimum number of subsets into which the vertex set V(G) can be partitioned so that each subset induces an acyclic graph. A graph G is called list vertex k-arborable if for any set L(v) of cardinality at least k at each vertex v of G, one can choose a color for each v from its list L(v) so that the subgraph induced by every color class is a forest. The smallest k for a graph to be list vertex k-arborable is denoted by ρl(G). Borodin, Kostochka and Toft (Discrete Math. 214 (2000) 101-112) first introduced the list vertex arboricity of G. In this paper, we prove that ρl(G)≤2 for any toroidal graph without 5-cycles. We also show that ρl(G)≤2 if G contains neither adjacent 3-cycles nor cycles of lengths 6 and 7.
Keywords :
Vertex arboricity , toroidal graph , structure , cycle
Journal title :
Bulletin of the Iranian Mathematical Society
Journal title :
Bulletin of the Iranian Mathematical Society