Optimal dependence on the Frostman constant

Determine the optimal dependence on the Frostman constant \(F_s\) in the intrinsic-energy estimate for angular measures \(\nu\) on the normal arc of the monomial curve \(\gamma_k(t)=(t,t^k)\), under the condition \(\nu(B(\omega,r))\le F_s\nu(\Omega_k)r^s\).

Background

The Frostman analysis yields a growth diagram for the intrinsic energy IR(ν)\mathcal I_R(\nu), but the final uniform estimates use a factor Fs2F_s^2. An intermediate active-pair estimate preserves more detailed information about FsF_s, suggesting that the quadratic dependence may not be optimal. The paper explicitly leaves the problem of identifying the sharp dependence unresolved.

References

The uniform bound obtained in the different regimes carries the factor F_s2; determining the optimal dependence on F_s remains open.

Normal-Direction Energy and Fourier Restriction for Convex Planar Curves  (2609.20643 - Vergara, 17 Sep 2026) in Remark 5.12, Section 5.2, “Angular Frostman regime”