Introduction to arithmetic groups

Arithmetic groups are fundamental groups of locally symmetric spaces. We will see how they are constructed, and discuss some of their important properties. For example, although the Q-rank of an arithmetic group is usually defined in purely algebraic terms, we will see that it provides important information about the geometry and topology of the corresponding locally symmetric space. Algebraic technicalities will be pushed to the background as much as possible. Dave Witte Morris (Univ. of Lethbridge) Introduction to arithmetic groups KAIST Geom Topology Fair 1 / 64 Introduction to Arithmetic Groups 1 What is a superrigid subgroup? 1 rigidity of linkages 2 group-theoretic superrigidity