Removal of the logarithmic factor in query complexity

Determine whether the remaining logarithmic factor in the query-complexity upper bound for estimating the state frame potential can be removed.

Background

The paper establishes a query complexity of approximately O~(t/ε)\widetilde{O}(\sqrt{t}/\varepsilon) for estimating the order-tt state frame potential, with the upper and lower bounds matching up to logarithmic factors. The authors explicitly identify removal of this residual logarithmic factor as a natural unresolved question.

References

A first natural question is whether the remaining logarithmic factor in the query upper bound can be removed.

Towards Optimal Quantum Estimators for State Frame Potential  (2608.24711 - Bao et al., 25 Aug 2026) in Section 6, Discussion