Universal monotonicity of support scaling exponents in dimensions d ≥ 3
Determine whether the upper support scaling exponents of a compact set A ⊂ R^d are universally nondecreasing in the index for all d ≥ 3; that is, prove or refute that s_0(A) ≤ s_1(A) ≤ ··· ≤ s_{d−1}(A) always holds when d ≥ 3.
References
Nevertheless, for spaces Rd where d\geq 3, whether eq:increasing-exp holds universally continues to be an unresolved open problem.
                — Review of Steiner formulas in Fractal Geometry via Support measures and Complex Dimensions
                
                (2509.05227 - Radunović, 5 Sep 2025) in Section 7, Support Contents and the Parallel Set Perspective