3-degenerate induced subgraph of a planar graph

Y. Gu, H. A. Kierstead, Sang-il Oum +2

A graph $G$ is $d$-degenerate if every non-null subgraph of $G$ has a vertex of degree at most $d$. We prove that every $n$-vertex planar graph has a $3$-degenerate induced subgrap…