Christian Kassel
CNRS - Université Louis Pasteur, Strasbourg
Recent developments on Artin's braid groups
There have been two recent interesting developments on braid groups: one is the
proof by Bigelow and Krammer that braid groups have finite-dimensional faithful
representations; another one is the construction by Dehornoy of an invariant
linear ordering on these groups (no such ordering was known before). In my
lecture I'll concentrate on Dehornoy's ordering and explain how it came up
unexpectedly in the study of a large cardinal axiom in set theory. I'll also
give an alternative topological construction of this ordering.