Chart description for hyperelliptic Lefschetz fibrations and their stabilization

Chart descriptions are a graphic method to describe monodromy representations of various topological objects. Here we introduce a chart description for hyperelliptic Lefschetz fibrations, and show that any hyperelliptic Lefschetz fibration can be stabilized by fiber-sum with certain basic Lefschetz fibrations. This is a joint work with Seiichi Kamada.