
School of Mathematics and Statistics
Jean Michel
Université Paris VII
Symmetric braids.
Friday November 30, 121pm, Carslaw 375.
Which braids have symmetries? This seemingly strange question leads
to interesting developments (which historically preceded the
question). A nontrivial result is that braids which are homotopic to
their symmetric have symmetric representatives. The proof involves
regular elements in reflection groups (in the sense of Springer)
and the BirmanKoLee monoid. The same question can be more generally
asked about braid groups of complex reflection groups. It can be
solved in the real case by using the dual braid monoid of David
Bessis.
