Existence of an optimal dense forest with constant error term

Determine whether there exists a dense forest F ⊂ R^d (for d ≥ 2) with finite density whose visibility satisfies V(ε) = O(ε^{-(d−1)}) as ε → 0; equivalently, ascertain whether the error term E(ε) in the representation V(ε) = ε^{-(d−1)} E(ε^{-1}) can be bounded by a constant (E(ε) ∈ O(1)).

Background

A dense forest is a subset F of Rd with finite density for which there exists a visibility function V(ε) such that any line segment of length V(ε) stays within distance ε of some point of F. Many constructions achieve V(ε) of order ε{-(d−1)} times a growing error term, with the best bound in this paper achieving a logarithmic error E(ε) ≍ ln(ε{-1}).

An ‘optimal’ dense forest would have a constant error term E(ε) ∈ O(1), yielding visibility V(ε) = O(ε{-(d−1)}). Whether such a set exists remains unresolved and represents a central target in minimizing visibility growth.

References

The lower bound for the error term, for an ‘optimal’ dense forest, has E(ε) ∈ O(1). It is not known if this lower bound is attainable by a dense forest.

A New Construction of Forests with Low Visibility  (2407.01633 - Kashkan, 2024) in Section 1 (Introduction)