Identify hyperbolic Coxeter pairs with looped diagrams
Determine whether bicolourable hyperbolic Coxeter diagrams containing loops satisfy the eigenvalue-sharing condition required to form Coxeter pairs between non-crystallographic and crystallographic groups.
References
As a natural next step to extend these results, it would be interesting to include those hyperbolic diagrams from that have loops but are bicolourable, and check whether the eigenvalue-sharing condition is met for the bicoloured Coxeter elements.
— Spacetime Quasicrystals and Computational Complexity Theory in the Road Towards Quantum Gravity
(2610.09855 - Mygdalas, 7 Oct 2026) in Chapter 7, Section 7.2, 'No Non-Crystallographic Foldings of Simplicial Hyperbolic Coxeter Graphs'