“…In retrospect, we observe that the three constructions for the Ω(n d ) lower bound in [17,13,5] are based on essentially the same simple idea. For the O(n d ) upper bound, Kaplan et al [17] use an elegant shifting technique and cite Boissonnat, Sharir, Tagansky, and Yvinec [8] for a similar analysis, and Backer and Keil [5] use essentially the same technique (which they call deflation-inflation) in their proof and cite (the Hence the maximum number of maximal empty boxes is Θ(n d ) for each fixed d. This means that any algorithm that computes a maximum-volume empty box by enumerating all maximal empty boxes is bound to be inefficient in the worst case. Indeed, by a standard result in parameterized complexity theory [21,Section 6.3], the aforementioned W[1]-hardness result of Giannopoulos, Knauer, Wahlström, and Werner [15,Theorem 3] implies that the existence of an exact algorithm running in n o(d) time is unlikely, i.e., unless the so-called Exponential Time Hypothesis (ETH) fails, i.e., unless 3-SAT can be solved in 2 o(n) time.…”