Inclusion-connectivity of reflexive polytopes in higher dimensions

Prove that the graph of d-dimensional reflexive lattice polytopes modulo unimodular equivalence, with adjacency defined by inclusion of representatives in a common lattice, is connected for dimensions d≥5.

Background

The paper defines a graph whose vertices are unimodular-equivalence classes of d-dimensional reflexive lattice polytopes and whose edges join classes admitting nested representatives. It proves that the Gorenstein weak F-equivalence conjecture in dimension d would imply connectedness of this graph.

Connectedness is known for dimensions at most four through classifications and prior results. The authors identify the higher-dimensional cases as unresolved, making this a concrete polyhedral consequence and an independent open problem related to the proposed Gorenstein refinement.

References

Nevertheless, \Cref{conj:gwf} remains highly nontrivial: \Cref{prop:polyhedral-consequence} below shows that its validity in dimension d would imply that the inclusion graph of d-dimensional reflexive lattice polytopes, modulo unimodular equivalence, is connected, which remains an open problem.

Counterexamples to Sato's Weak F-Equivalence Conjecture and a Gorenstein Refinement  (2608.18054 - Chakravarty et al., 18 Aug 2026) in Section 7.1, immediately before and after Proposition 7.2