Abstracts for the Seminar
 Discrete Geometry and Combinatorics
Spring 2012

Speaker:  R. Connelly
Title:  Periodic Planar Disk Packings
Time: 2:30 PM, Monday, February 6, 2012
Place:  Malott 206

Abstract:

Several conditions are given when a packing of equal disks in a torus is locally maximally dense, where the torus is defined as the quotient of the plane by a two-dimensional lattice. Conjectures are presented that claim that the density of any strictly  jammed packings, whose graph does not consist of all triangles and the torus lattice is the standard triangular lattice, is at most $\frac{n}{n+1}\frac{\pi}{\sqrt{12}}$, where $n$ is the number of packing disks.  Several classes of collectively jammed packings are presented where the conjecture holds.