Periodic orbit-closure conjecture for exact-cluster tilings
Let be an exact cluster with full affine span, and let be an -tiling. The orbit closure of is
A tiling is -periodic if it has a nonzero period in .
Periodic orbit-closure conjecture. The orbit closure
contains a -periodic -tiling.
This conjecture would extend the expected link between low pattern complexity and periodicity to tilings by possibly non-convex windows. The paper states that its counterexample refutes this conjecture, so it is disproved.
References
Primary source
Abhishek Khetan, “A Counterexample to Nivat's Conjecture for a Non-Convex Window of Full Affine Span”, arXiv:2607.09830 (2026).
Additional references
3 papers in this index state this conjecture (2013–2026). The statement above is taken from the most recent of them; the others are arXiv:2507.12654, arXiv:1312.0386.
Progress summary
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Solutions 0
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