# Knot at Lunch on January 30 2008

## Invitation

Dear Knot at Lunch People,

We will have our next lunch on Wednesday January 30, at the usual place, Bahen 6180, at 12 noon.

As always, please bring brown-bag lunch and fresh ideas. The agenda: we may talk a bit about Artin's theorem on the braid group and automorphisms of the free group, or we may talk about something else.

As always, if you know anyone I should add to this mailing list or if you wish to be removed from this mailing list please let me know. To prevent junk accumulation in mailboxes, I will actively remove inactive people unless they request otherwise.

Best,

Dror.

## Another Invitation

Madre, at Aluna Theatre, January 29 - February 17, featuring Hernando's daughter Juliette Burgos.

## Possible Agenda

• The Artin representation of the pure braid group on $n$ strand $PB_n$ into the automorphism group $\operatorname{Aut}(F_n)$ of the free group on $n$ generators $F_n$ (hey, I'm not even sure that's what it's called!).
• Abstract definition.
• Practical computation from the Wirtinger presentation.
• Practical computation by stirring the soup.
• Properties.
• Artin's theorem (is that what it's called?).
• Is there an Artin's theorem for pure virtual braids?
• What is the finite type completion of $\operatorname{Aut}(F_n)$? How about some of its obvious subgroups?