Deep hole

in a lattice

Let $P$ be a collection of points in $\mathbf R$ (usually a lattice). A hole is a point of $\mathbf R$ whose distance to $P$ is a local maximum. A deep hole is a point of $\mathbf R$ whose distance to $P$ is the absolute maximum (if such exists).

If $P$ is a lattice, then the holes are precisely the vertices of the Voronoi cells (cf. Voronoi diagram; Parallelohedron).

References

[a1]	J.H. Conway, N.J.A. Sloane, "Sphere packings, lattices and groups" , Grundlehren , 230 , Springer (1988) pp. 6; 26; 33; 407