# Rational homology disks and symplectic topology

Thursday, October 8, 2009 -

4:30pm to 6:30pm

Surface singularities admitting a smoothing with the homology of the 4-disk (a so-called rational homology disk, QHD) play central role in the construction of exotic 4-manifolds through the "rational blow down process." Applying various forms of gauge theory we derive obstructions for a singularity to admit such smoothings. Using symplectic topology we classify all starshaped resolution graphs with QHD smoothings.

Speaker:

Andras Stipsicz

Renyi Institute, Hungary

Event Location:

Fine Hall 314