Skip to main


As part of Mason's Safe Return to Campus Plan, all classes and associated instructional activities—including final exams—will be conducted virtually beginning November 30, while most campus facilities will remain open. Visit Mason’s Safe Return to Campus Plan for COVID-19 updates.

Math equations

Mathematics Colloquium: Three-dimensional affine crystals

Speaker: Bill Goldman, University of Maryland

Title: Three-dimensional affine crystals

Abstract: Crystallographers in the 19th century developed the notion of a crystallographic group to express the geometric symmetries of crystals. The classical theorems of Bieberbach gives a qualitative classification of crystallographic groups in terms of finite groups of integer matrices. In modern terms, this led to to the classification of discrete groups of isometries of Euclidean space, or, equivalently, Riemannian manifolds of zero curvature. The more general theory in affine geometry is much richer and more interesting. In this talk I will describe the recent classification in dimension three, and the intricate relationships to hyperbolic non-Euclidean geometry as well as the geometry of special relativity.

Time: Friday, September 19, 2014, 3:30-4:20 p.m.

Place: Exploratory Hall, room 4106

Refreshments will be served at 3:00 p.m.