The Hochbaum–Nishizeki–Shmoys conjecture on polynomial-time edge coloring

From papers

Let GG be a multigraph, let Δ(G)\Delta(G) denote its maximum degree, and let

Γ(G):=maxHGE(H)12V(H)\Gamma(G):=\max_{H\subseteq G}\left\lceil\frac{|E(H)|}{\left\lfloor\frac{1}{2}|V(H)|\right\rfloor}\right\rceil

be its density. A proper edge-coloring assigns colors to the edges so that adjacent edges receive different colors.

Hochbaum–Nishizeki–Shmoys conjecture. There exists a polynomial-time algorithm that finds a proper edge-coloring of every multigraph GG using maxΔ(G)+1,Γ(G)\max\\{\Delta(G)+1,\Gamma(G)\\} colors.

The paper states that its main theorem confirms this conjecture by providing such an algorithm. Therefore the conjecture is solved.

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Sources & referencesView supporting material

Primary source

Guangming Jing, “On Edge Coloring of Multigraphs”, arXiv:2308.15588 (2026).

Additional references

2 papers in this index state this conjecture (2019–2023). The statement above is taken from the most recent of them; the others are arXiv:1901.10316.

Solutions 0

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