Department of Mathematics Colloquium

University of Idaho

Spring 2012

Thursday,  March 29, 3:30-4:20 pm, room TLC 032

Refreshments in Brink 305 at 3:00 pm

Quasicrystals and Impossible Symmetry:  three streams of mathematics converging


Enrico Au-Yeung

Department of Mathematics

University of British Columbia


The recent Nobel Prize in chemistry was awarded to Dan Shechtman for his discovery of Quasicrystals in 1982.  But long before 1982, mathematicians were playing around with these objects.  Roger Penrose was thinking of Penrose tiling of the plane, Yves Meyer was thinking of Meyer sets in connection to harmonic analysis, and Delaunay was thinking about sets that are named after him in the triangulation of the plane.  All these three streams of mathematics converge and they pre-dated the actual discovery of quasi-crystals in nature.  Why? Because such mathematical objects must be beautiful to study to begin with. In this lively and entertaining talk, I will make the mathematics behind quasi-crystals highly accessible to a wide audience. I will discuss different formulations for such objects with unusual symmetry, provide some motivation, and show that some of the different formulations are equivalent.