The Dehn surgery characterization of the trefoil and the figure eight   knot
  We give a Dehn surgery characterization of the trefoil and the figure eight knots. These results are gotten by combining surgery formulas in Heegaard Floer homology from an earlier paper with the characterization of these knots in terms of their knot Floer homology given in a recent paper of Ghiggini. 
Peter Ozsvath and Zoltan Szabo