Hamiltonicity conjecture for the face lattice of every polytope

From papers

Let PP be a polytope of dimension d1d\geq 1. Its face lattice L(P)L(P) consists of all faces of PP, ordered by inclusion, and G(L(P))G(L(P)) is the cover graph of this lattice: its vertices are the faces of PP, with two faces adjacent when one is a subface of the other and their dimensions differ by 11.

Hamiltonicity conjecture. The graph G(L(P))G(L(P)) has a Hamiltonian cycle.

Such a cycle would give a Gray code listing of all faces of PP, in which consecutive faces differ by a single cover relation in the face lattice. The source presents this as a brave conjecture and notes that the question appears to be novel; the available context gives no resolution.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Nastaran Behrooznia, Sofia Brenner, Arturo Merino, Torsten Mütze, Christian Rieck and Francesco Verciani, “Listing faces of polytopes”, arXiv:2412.02584 (2026).

Additional references

5 papers in this index state this conjecture (2003–2024). The statement above is taken from the most recent of them; the others are arXiv:2205.15228, arXiv:1611.06401, arXiv:1206.4846, arXiv:math/0303084.

Solutions 0

No solutions have been posted yet.