  We explore certain restrictions on knots in the three-sphere which admit
non-trivial Seifert fibered surgeries. These restrictions stem from the
Heegaard Floer homology for Seifert fibered spaces, and hence they have
consequences for both the Alexander polynomial of such knots, and also their
knot Floer homology. In particular, we show that certain polynomials are never
the Alexander polynomials of knots which admit homology three-sphere Seifert
fibered surgeries. The knot Floer homology restrictions, on the other hand,
apply also in cases where the Alexander polynomial gives no information, such
as the Kinoshita-Terasaka knots.
