Affine length functions and actions on non-archimedean trees

Speaker: Dr Shane O'Rourke (CIT)

Time: 4:00PM
Date: Mon 22nd February 2010

Location: Mathematical Sciences Seminar Room

We attempt to unify the theories of (1) isometric actions on Lambda-trees (where Lambda is a linearly ordered abelian group), and particularly based length functions associated with such actions; and (2) affine actions on R-trees, as studied by I. Liousse.

While much of these theories can be carried over to this new setting, we will describe some of the interesting examples of groups that have (fixed-point) free affine actions, but which do not admit actions as in (1) or (2) above.

(This talk is part of the Algebra/Claude Shannon Institute series.)