Involution-free realizations for non-generalized-dihedral infinite groups

Establish whether every infinite group that is not generalized dihedral admits an involution-free realization of the inverse-pair symmetry group \(\Xi(G)\), and hence an oriented regular representation.

Background

An oriented regular representation (ORR) is a directed Cayley graph Cay→(G,T)Cay^{\to}(G,T) with T∩T−1=∅T\cap T^{-1}=\varnothing, generating connection set TT, and automorphism group equal to the right-translation group R(G)R(G). The paper observes that an involution-free realization of Ξ(G)\Xi(G) would yield an ORR by orienting each inverse pair in the connection set.

The paper establishes such realizations for uncountable abelian groups AA with ∣2A∣=∣A∣|2A|=|A| and for uncountable generalized dicyclic groups with ∣2A∣=∣A∣|2A|=|A|, but does not settle the question for all infinite groups outside the generalized-dihedral case. It specifically notes that the regular-case construction does not directly resolve the issue because deleting involutions can create infinitely many error pairs.

References

We ask whether every infinite group that is not generalized dihedral admits an involution-free realization of \Xi(G), and hence an ORR. The regular-case construction of Section~4 does not answer this directly: removing the involutions from a bit-one layer creates error pairs whose degree is |Hg\cap\operatorname{Inv}(G)| for g in that layer, which is infinite for every admissible countable core in, for example, D_\infty\times B\times\mathbb Z with B an uncountable Boolean group.

— Watkins's conjecture holds for all infinite groups  (2610.01049 - Sutherland, 1 Oct 2026) in Remark 'Oriented representations' (Section 7.2, immediately before Section 'Computational checks and further questions')