Toshiki Abe

collaborators

2 papers

math.CO2026

On the number of 4-contractible edges in plane triangulations

Toshiki Abe, Michitaka Furuya, Raiji Mukae +1

In 2007, Ando and Egawa proved a theorem which provides a lower bound on the number of contractible edges preserving $4$ -connectedness in $4$ -connected graphs. In this paper, we re…

math.CO2019

The Alon-Tarsi number of $K_{5}$ -minor-free graphs

Toshiki Abe, Seog-Jin Kim, Kenta Ozeki

In this paper, we show the following three theorems. Let $G$ be a $K_{5}$ -minor-free graph. Then Alon-Tarsi number of $G$ is at most $5$ , there exists a matching $M$ of $G$ such that…

On the number of 4-contractible edges in plane triangulations

The Alon-Tarsi number of K5​-minor-free graphs

The Alon-Tarsi number of $K_{5}$ -minor-free graphs