Type: Seminar

Distribution: World

Expiry: 18 Apr 2008

CalTitle1: Algebra Seminar: Hillman -- Finite index endomorphisms of mapping tori of free group automorphisms

Auth: anthonyh@asti.maths.usyd.edu.au

A group G is hopfian if every onto endomorphism f:G->G is an isomorphism.
We shall describe some extensions of this notion, and examine the case of
semidirect products G=F(r) \rtimes_\phi Z, where \phi is an automorphism of the
free group F(r). (Such groups G are the "mapping tori" of the title.)
Although these notions derive from topology, the arguments are primarily algebraic.
This is based on joint work with M.Bridson, D.Groves and G.Martin. |