### Joint GT-UGA Seminar at GT - The ribbon genus of a knotted surface

- Series
- Geometry Topology Seminar
- Time
- Monday, October 1, 2018 - 15:30 for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Jason Joseph – UGA

The knot group has played a central role in classical knot theory
and has many nice properties, some of which fail in interesting ways for
knotted surfaces. In this talk we'll introduce an invariant of
knotted surfaces called ribbon genus, which measures the failure of a
knot group to 'look like' a classical knot group. We will show that
ribbon genus is equivalent to a property of the group called Wirtinger
deficiency. Then we will investigate some examples
and conclude by proving a connection with the second homology of the
knot group.