Conférencier: Duncan McCoy, UT Austin

Résumé/Abstract: One of the simplest ways of constructing 3-manifolds is through Dehn surgery. Given a knot in the 3-sphere, we perform Dehn surgery by cutting out a tubular neighborhood of the knot and gluing back in another solid torus. As well as being of intrinsic interest, Dehn surgery has a variety of applications in low-dimensional topology. The development of Heegaard Floer homology has led to a recent flurry of progress on Dehn surgery problems. I will discuss a variety of topics, including lens space surgeries, alternating knots with unknotting number one and characterizing slopes, to illustrate this progress. In particular, I wish to show how results from Heegaard Floer homology can be combined with older geometric techniques.