Abstract:
Let G be group and X a subset. The width of X in G is the minimal integer n such that every element in the subgroup generated by X is a product of at most n elements of X or their inverses. If no such n exists, we say that the width is infinite. In this talk we will explain how, for certain groups G and certain sets X, we can use non-standard models of the first order theory of G to answer questions about width.