Possible orders of weighted two-dimensional combinatorial groups

Determine whether a two-dimensional walk model with non-trivial step weights can have a combinatorial group of order greater than 10, or prove that order 10 is the maximal possible order.

Background

The combinatorial group associated with a two-dimensional walk model is dihedral and may be finite or infinite. For unweighted models, the paper recalls that the finite possibilities have orders 4, 6, or 8; allowing non-trivial weights yields an example of order 10.

The authors state that no higher order is believed to occur, leaving unresolved whether finite weighted two-dimensional models with larger combinatorial groups exist. Establishing the maximal possible order would complete the finite-order classification in this weighted setting.

References

If non-trivial weights are allowed, then the group can be of order $10$, see Sec.~7, and it is believed that no higher order is possible.

Enumeration of walks in multidimensional orthants and reflection groups  (2501.05654 - Gohier et al., 10 Jan 2025) in Section “Dimension two,” Applications