Department Colloquium

Department of Mathematics
Princeton University



March 28th, 2001


Flowing crystals: Some Mathematical Challenges Posed by Materials Science


During the past 30 years, there has been much mathematical activity concerning minimal surfaces, soap films and soap bubble clusters. There has also been much mathematical activity concerning motion by mean curvature and other motions which reduce surface area. Simultaneously, the interaction of mathematics and materials science has grown. Most metals, semiconductors, and ceramics are made up of atoms in locally ordered arrays, called crystals, which make interfaces with other materials or with crystals having different orientations. The interfaces are often regarded as two-dimensional surfaces which are somewhat like a soap bubble cluster. Furthermore, crystals can grow or shrink, with reduction of surface energy often a major influence on that motion. The ways in which crystals are both like and unlike soap films leads to some fascinating mathematical problems. Results that have been proved, new problems that have been recently formulated, and long-standing open problems will be surveyed.