Extension of the single-agent lower bound to the full feasible range

Determine whether the lower bound for one deterministic agent with flags in vertex-permuted dynamic rings, currently proved for \(\delta\geq 2n\), also holds throughout the full feasible range \(\delta\geq\lceil(n-1)/2\rceil\).

Background

For the restricted vertex-permuted ring class VP(δ)VP(\delta), the paper establishes feasibility precisely when δ(n1)/2\delta\geq\lceil(n-1)/2\rceil. For a single deterministic agent equipped with flags, it proves an upper bound of δ(n1)\delta(n-1) and a matching asymptotic lower bound of order δn\delta n, but the lower-bound construction is established only under the stronger assumption δ2n\delta\geq 2n.

The unresolved issue is whether the same asymptotic lower bound, and consequently the tight characterization of single-agent search time, remains valid for every feasible value of δ\delta, including the interval (n1)/2δ<2n\lceil(n-1)/2\rceil\leq\delta<2n.

References

It would be interesting to know whether the same bound holds for the full feasible range \delta\geq \lceil(n-1)/2\rceil.

Online Treasure Hunt in Vertex-Permuted Dynamic Rings  (2609.11013 - Ayoubi et al., 10 Sep 2026) in Section 7, Conclusion and open problems