Implication from cone energy estimates to ring or sum–product theorems

Determine whether an improvement over the established 3-energy estimate for fractal Katz–Tao sets on the truncated cone implies a ring theorem or a sum–product theorem.

Background

The paper discusses a known connection between improved energy estimates for the parabola and the discretized ring problem, together with Furstenberg-set and sum–product methods. It then contrasts this with the cone setting.

Because the cone has separate radial and angular variables that do not form the same one-dimensional additive–multiplicative structure, the authors explicitly state that they do not know whether improved cone energy yields a comparable ring or sum–product consequence.

References

We do not know an analogous implication from improved energy on the cone to a ring or sum–product theorem.

— Sharp $L^6$ Fourier moments and (3,$δ$)-energy estimates for fractal measures on the truncated cone in $\R^3$  (2610.23679 - Demeter, 16 Oct 2026) in Remark 1.4 (Energy and the ring problem), Section 1.2, p. 4