#
Geometry-Topology Seminar

Unless otherwise noted, all talks are at 1:30 in Ryerson 358.

## Spring 1999

- March 23
**Jim Davis
**

**Oriented matroids, MacPhersonians and
characteristic classes**

Note: This talk will be in E206.

- April 8
**Barak Weiss
**

**On sets invariant under the action of the diagonal group**

An abstract is available here.

- April 13
**David Witte
**

**Superrigid subgroups of solvable Lie groups**

- April 27
**D. Kleinbock
**

**TBA**

- April 29
**Shmuel Weinberger
**

**The fractal geometry of Riem/Diff**

- May 4
**Joel Hass
**

**The computational complexity of unknotting**

- May 6
**Shmuel Weinberger
**

**The fractal geometry of Riem/Diff II**

- May 11
**Matthias Schwarz
**

**On the periodic point problem for Hamiltonian automorphisms**

- May 13
**Brendan Weichert
**

**Self-maps of C^n tangent to the identity**

- May 18
**Kent Orr
**

**TBA**