Classical upper bounds for slice genera

Using elementary 3-dimensional invariants for knots in 3-space, we
will provide surprising upper bounds on the topological slice
genus---a 4-dimensional measure of complexity based on Fox's
sliceness. These upper bounds are established by crucially invoking
Freedman's Disk Theorem. As an application, strong
differences to the smooth notion of sliceness for knots are
established.
This talk is based on ongoing work with Lukas Lewark with a special
appearance by joint work with Duncan McCoy.