Stefan Behrens

I'm a low dimensional topologist. I mostly care about smooth, 4-dimensional manifolds and anything that comes with the territory.

Here are some things I actively care about:
* maps from 4-manifolds to surfaces and families thereof (Lefschetz, broken, wrinkled,...)
* diagrammatic descriptions of 4-manifolds
* intersection forms of 4-manifolds with boundary
* Heegaard Floer homology, especially with twisted coefficients

I'm also curious about these things:
* Parameterized Morse theory (aka Cerf theory)
* Seiberg Witten theory (especially in comparison to Heegaard Floer theory)
* any kind of Floer theory, for that matter
* diffeomorphism groups of surfaces and 3-manifolds