错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

On the packing density of Lee spheres

  • Ang Xiao,
  • Yue Zhou

摘要

Based on the packing density of cross-polytopes in \({\mathbb {R}}^n\) R n , more than 50 years ago Golomb and Welch proved that the packing density of Lee spheres in \({\mathbb {Z}}^n\) Z n must be strictly smaller than 1 provided that the radius r of the Lee sphere is large enough compared with n, which implies that there is no perfect Lee code for the corresponding parameters r and n. In this paper, we investigate the lattice packing density of Lee spheres with fixed radius r for infinitely many n. First we present a method to verify the nonexistence of the second densest lattice packing of Lee spheres of radius 2. Second, we consider the constructions of lattice packings with density \(\delta _n\rightarrow \frac{2^r}{(2r+1)r!}\) δ n 2 r ( 2 r + 1 ) r ! as \(n\rightarrow \infty \) n . When \(r=2\) r = 2 , the packing density can be improved to \(\delta _n\rightarrow \frac{2}{3}\) δ n 2 3 as \(n\rightarrow \infty \) n .