## Decision problems for fundamental groups of 3-manifolds.

Stefan Friedl

Regensburg

Abstract

The word problem for a group asks for an algorithm which can determine whether or not a given element in a group is trivial. Similarly the membership problem asks for an algorithm which can determine whether or not a given element lies in a given subgroup. We will discuss these two problems for the fundamental groups of 3-manifolds. No previous knowledge of 3-manifold topology is required.