Our next seminar will be this Thursday, April 20, at 3:00 PM in Weber 201. Our speaker is Tobias Rossmann who is visiting from the University of Galway. There will also be a seminar lunch at noon. If you are interested in joining please meet in the lobby a few minutes before 12.
Title:
Tame and wild orbits of unipotent groups derived from graphs
Abstract:
I’ll describe two recent projects devoted to the enumeration of orbits of Z-defined unipotent groups over finite fields. In both cases, graph-theoretic constructions play key roles. What sets the two projects apart is that in one case, the numbers of orbits turn out to be extremely tame (namely polynomial in the size of the field), whereas in the other case they end up being “approximately wild” in a geometric sense.