Critical inverse-energy conjecture and optimal explicit embedding

Prove or refute that there is an absolute constant c>0 such that, for every n and every pair of distinct integer partitions λ,μ of n, the critical dyadic energy of the realizable Ferrers-staircase difference v_{λ,μ} satisfies 𝓔(v_{λ,μ}) ≥ c‖v_{λ,μ}‖₁²/√n; determine whether the explicit coordinate F^(1/4), or another explicit coordinate, has class-optimal Euclidean distortion Θ(n^(1/4)) and O(n)-time computability.

Background

The paper introduces the critical dyadic coordinate F1/4 on Ferrers staircase functions and proves an unconditional distortion bound O(n1/4(log n)1/4). The remaining logarithmic factor arises from estimating the octave-localized total variation by Cauchy–Schwarz.

Conjecture 5.18 asserts the stronger inverse-energy inequality that would remove this factor and, by Corollary 5.20, would yield an explicit deterministic O(n)-time embedding with class-optimal distortion Θ(n1/4). The authors verify the conjecture on sign-coherent, balanced, and geometrically distributed octave-spectrum sub-cones, but leave the general tall, sign-incoherent, flat-spectrum regime unresolved. They also separately ask whether some explicit coordinate other than F1/4 can achieve the optimal order.

References

The remaining gap is one inequality, and it is open. What separates F{(1/4)} from the class-optimal order n{1/4} is exactly the difference between ∑_i√{τ_i} and √{∑_iτ_i} in the display above, that is, whether a flat octave spectrum can occur on the realizable cone. We isolate this as the critical inverse-energy conjecture (Conjecture~\ref{conj:5.18}) rather than as a programme. We verify it on three sub-cones where it is elementary (Proposition~\ref{prop:5.19}), and an exactly solvable extremal family caps its best possible constant at 2/3 (Proposition~\ref{prop:5.21}). But we have no approach to the general case, and we claim none.

Cluster-Graph Edit Distance: Metric Proxies, Multiscale Embeddings, and Complexity  (2608.17990 - Liu et al., 18 Aug 2026) in Conjecture 5.18 and Section 7, Open problems, item 1

Conjecture~\ref{conj:5.18} asks only for the order; one may ask instead for the whole extremal profile, the least critical energy compatible with prescribed ‖v‖₁ and TV(v), of which Proposition~\ref{prop:5.21} computes one point.

Cluster-Graph Edit Distance: Metric Proxies, Multiscale Embeddings, and Complexity  (2608.17990 - Liu et al., 18 Aug 2026) in Section 7, Further directions

Finally, Theorem~\ref{thm:5.8} rules out one specific coordinate map; whether every map that is linear in u_λ is stuck at Ω(n{1/4}√{\log n}), which would force any resolution of Problem 1 through weighted or nonlinear coordinates, we do not know.

Cluster-Graph Edit Distance: Metric Proxies, Multiscale Embeddings, and Complexity  (2608.17990 - Liu et al., 18 Aug 2026) in Section 7, Further directions