Spanning Trees with Few Leaves in Almost Claw-Free Graphs

Abstract:

      A spanning tree with no more than 3 leaves is called a spanning 3-ended tree. In this paper, we prove that if $G$ is a $k$-connected ($k\geq 2$) almost claw-free graph of order $n$ and $\sigma_{k+3}(G)\geq {n+k+2}$, then $G$ contains a spanning 3-ended tree, where $\sigma_k(G)=\min\{\sum_{v\in S}{\rm deg}(v):S$ is an independent set of $G$ with $|S|=k\}$.