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ISSN (electronic): 1364-0380
ISSN (print): 1465-3060
Pessimal packing shapes

Yoav Kallus

Geometry & Topology 19 (2015) 343–363
Abstract

We address the question of which convex shapes, when packed as densely as possible under certain restrictions, fill the least space and leave the most empty space. In each different dimension and under each different set of restrictions, this question is expected to have a different answer or perhaps no answer at all. As the problem of identifying global minima in most cases appears to be beyond current reach, in this paper we focus on local minima. We review some known results and prove these new results: in two dimensions, the regular heptagon is a local minimum of the double-lattice packing density, and in three dimensions, the directional derivative (in the sense of Minkowski addition) of the double-lattice packing density at the point in the space of shapes corresponding to the ball is in every direction positive.

Keywords
packing, convex body, lattice, density
Mathematical Subject Classification 2010
Primary: 52A40
Secondary: 52C15, 52C17
References
Publication
Received: 11 August 2013
Accepted: 5 June 2014
Published: 27 February 2015
Proposed: Dmitri Burago
Seconded: Walter Neumann, Yasha Eliashberg
Authors
Yoav Kallus
Santa Fe Institute
1399 Hyde Park Road
Santa Fe, NM 87501
USA