Disks with special properties of densest packings
The author describes a method how to construct a disk D such that all its densest packings are nonperiodic. The disks used are starshaped unions of two convex sets. As an application the author considers a disk such that no periodic packing has minimal density, a disk which has precisely n densest periodic packings and a disk which locally can be packed denser than globally.
scientific article; zbMATH DE number 4208965