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From the 1 of 10 linked papers with an AI index.

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12 papers

math.CO2026

Three-edge-coloring apex cubic graphs

Yuta Inoue, Ken-ichi Kawarabayashi, Rintaro Matsuo +3

A graph is \emph{apex} if has a vertex such that is planar. We prove that every -connected apex cubic graph is three-edge-colorable. This result gives the fina…

cs.DS2026

The Balanced Four-Color Theorem

Ken-ichi Kawarabayashi, Hirotaka Yoneda, Masataka Yoneda

The paper proves that every planar graph with at least three vertices can be 4‑colored so that each color class contains fewer than half of the vertices, and provides an O(n log n)…

math.CO2026

Connectivities for k-knitted graphs and for minimal counterexamples to Hadwiger's Conjecture

Ken-ichi Kawarabayashi, Gexin Yu

For a given subset of a graph , the pair is \emph{knitted} if for every partition of into non-empty subsets , there exist pa…

cs.DM2026

Well-Quasi-Ordering Eulerian Digraphs: Bounded Carving Width

Dario Cavallaro, Ken-ichi Kawarabayashi, Stephan Kreutzer

We prove that every class of Eulerian directed graphs of bounded carving width (equivalently of bounded degree and treewidth) is well-quasi-ordered by strong immersion. In fact, we…

cs.DS2026

EPTAS for Hard Graph Cut Problems for Dense Graphs

Kaisei Deguchi, Ken-ichi Kawarabayashi, Hiroaki Mori

Everywhere--dense graphs are defined as graphs on vertices in which every vertex has degree at least for some constant . Approximation schemes are vital for ha…

math.CO2026

The Four Color Theorem with Linearly Many Reducible Configurations and Near-Linear Time Coloring

Yuta Inoue, Ken-ichi Kawarabayashi, Atsuyuki Miyashita +3

We give a near-linear time 4-coloring algorithm for planar graphs, improving on the previous quadratic time algorithm by Robertson et al. from 1996. Such an algorithm cannot be ach…