Geometric ideal triangulation conjecture

For every finite-volume cusped hyperbolic 33-manifold MM, there exists a finite ideal triangulation of MM whose tetrahedra are realized as positively oriented geodesic ideal tetrahedra in H3\mathbb{H}^3, with the induced geometric structure equal to the complete hyperbolic structure on MM.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed solved

A new unrefereed preprint claims that every cusped hyperbolic three-dimensional space has a geometric ideal triangulation, but the claim has not been independently checked.

The conjecture asserts that every finite-volume cusped hyperbolic 33-manifold admits a geometric ideal triangulation. Earlier literature treated this universal existence statement as open; no proposer or original date is identified in the retrieved sources.

Known results

  • Feng and Ge: combinatorial Ricci flow converges exactly when the relevant triangulation is geometric, but universal existence remains open.
  • General restricted classes include punctured-torus bundles, two-bridge link complements, certain arborescent link complements, and covers of these spaces.
  • The conjecture is true virtually: a finite cover admits a geometric ideal triangulation.
  • Zhao, February 5, 2026: an edge-valence bound of at least 99 gives convergence and a geometric truncated-tetrahedral decomposition, improving the previous bound from 1010 to 99.

September 2026 claimed universal proof

On September 23, 2026, a report identified Huabin Ge’s preprint Geometric ideal triangulations of hyperbolic 3-manifolds, which asserts the universal existence statement. If correct, it would remove the longstanding obstruction; the claim is unrefereed and unverified.

Current status (as of September 2026): Ge’s preprint claims a universal solution, but that claim remains unverified; restricted and virtual cases are established, and independent confirmation is needed.

Sources

Solutions 0

No solutions have been posted yet.