The Linear \(2\)-Arboricity of Outerplanar Graphs

Ko-Wei Lih1, Li-Da Tong2, Wei-Fan Wang3
1Institute of Mathematics Academia Sinica Taipei 115, Taiwan
2Department of Applied Mathematics National Sun Yat-sen University Kaohsiung 804, Taiwan
3Department of Mathematics Zhejiang Normal University Jinhua, Zhejiang 321004, China

Abstract

The linear \(2\)-arboricity \(la_2(G)\) of a graph \(G\) is the least integer \(k\) such that \(G\) can be partitioned into \(k\) edge-disjoint forests, whose component trees are paths of length at most \(2\). We prove that \(la_2(G) \leq \lfloor \frac{\Delta(G) + 4}{2} \rfloor\) if \(G\) is an outerplanar graph with maximum degree \(\Delta(G)\).