Robert Tang, formerly of Sydney University, now at Warwick, will give a special seminar. Abstract: The mapping class group of a surface is its group of orientation-preserving self-homeomorphisms up to homotopy. This group acts naturally on many different spaces and so, using ideas from geometric group theory, we can learn not only about the geometry of those spaces but also about the group itself. One such space is the curve complex, whose vertices are the homotopy classes of essential non-peripheral loops embedded on the surface. I will talk about the basic properties and some key results regarding the mapping class group and the curve complex. If time permits, I will also talk about a result regarding covering maps between surfaces and the induced relation between their curve complexes. Refreshments will be available if there is a volunteer to purchase them. Contact me if you would like to do this. Mary Myerscough PG Director