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.
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.
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.
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.