2002/07/20 by J. H. Conway, E. M. Rains, N. J. A. Sloane
Mathematics · #math.CO #math.NT #msc:11H06
published as Canadian J. Math., 51 (1999), 1300-1306 · 7 pages; dedicated to H.S.M. Coxeter
arxiv created 2002/07/20 · arxiv updated 2009/11/30
Partial answers are given to two questions. When does a lattice Lambda contain a sublattice Lambda' of index N that is geometrically similar to Lambda? When is the sublattice "clean", in the sense that the boundary of the Voronoi cells for Lambda ' do not intersect Lambda?