Y. Otachi

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20112026

most citedVertex Deletion Problems on Chordal Graphs

1 citations · 1 across the 26 of their papers we have counts for

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4 papers · 1 filter

math.CO2026

Treewidth of the $n \times n$ toroidal grid

Tatsuya Gima, Hiraku Morimoto, Yuto Okada +1

In this paper, we show that the treewidth of the $n \times n$ toroidal grid is $2 n - 1$ for all $n \geq 5$ . This closes the gap between the previously known upper bound of $2 n - 1$ (Ell…

math.CO2026

On Edge-Disjoint Maximal Outerplanar Graphs

Yuto Okada, Yota Otachi, Lena Volk

We provide two constructions for $t$ edge-disjoint maximal outerplanar graphs on every number of $n \geq 4 t$ vertices. The bound on the minimum number of vertices is tight. These c…

math.CO2025

Interval Graphs are Reconstructible

Irene Heinrich, Masashi Kiyomi, Yota Otachi +1

A graph is reconstructible if it is determined up to isomorphism by the multiset of its proper induced subgraphs. The reconstruction conjecture postulates that every graph of order…

math.CO2024

An improved spectral lower bound of treewidth

Tatsuya Gima, Tesshu Hanaka, Kohei Noro +2

We show that for every $n$ -vertex graph with at least one edge, its treewidth is greater than or equal to $n λ_{2} / (Δ + λ_{2}) - 1$ , where $Δ$ and $λ_{2}$ are the maximum degree a…

Treewidth of the n×n toroidal grid

On Edge-Disjoint Maximal Outerplanar Graphs

Interval Graphs are Reconstructible

An improved spectral lower bound of treewidth

Treewidth of the $n \times n$ toroidal grid