Kotzig’s perfect one-factorisation conjecture

For every sufficiently large even n, how many edge-disjoint perfect matchings of K_n can be chosen so every pair forms a Hamilton cycle? The asymptotic target is at least (1−ε)n for each ε>0.

Why it matters and what counts as progress

Why it matters: It seeks an almost-complete pairwise-perfect matching collection uniformly across all large even orders.

What counts as progress: Increase the pairwise-Hamiltonian perfect-matching collection toward a full factorization for every large even order.

How the problem developed

  1. 10 Jul 2026 · Asymptotic partial result [1]

    Yangyang Cheng and Amedeo Sgueglia Constructed factorizations of Kₙ in which (1−o(1))n of the n−1 perfect matchings pair to form Hamilton cycles.

AI contribution

Sources

  1. Yangyang Cheng and Amedeo Sgueglia, The perfect 1-factorisation conjecture holds asymptotically
  2. Cheng and Sgueglia, The perfect 1-factorisation conjecture holds asymptotically
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