Sala Seminari (Dip. Matematica).
I will introduce the operation of torus surgery in the 4-sphere, and describe some recent results concerning which 4-manifolds can beproduced in this way and the uniqueness of such descriptions. As motivation I will discuss analogous results and problems about Dehn surgery on knots in the 3-sphere. I will also discuss some applications toembedding 3-manifolds into 4-manifolds.