  Fintushel and Stern have proved that if S \subset X is a symplectic surface
in a symplectic 4-manifold such that S has simply-connected complement and
nonnegative self-intersection, then there are infinitely many topologically
equivalent but smoothly distinct embedded surfaces homologous to S. Here we
extend this result to include symplectic surfaces whose self-intersection is
bounded below by 2-2g, where g is the genus of S.
  We make use of tools from Heegaard Floer theory, and include several results
that may be of independent interest. Specifically we give an analogue for
Ozsvath-Szabo invariants of the Fintushel-Stern knot surgery formula for
Seiberg-Witten invariants, both for closed 4-manifolds and manifolds with
boundary. This is based on a formula for the Ozsvath-Szabo invariants of the
result of a logarithmic transformation, analogous to one obtained by
Morgan-Mrowka-Szab\'o for Seiberg-Witten invariants, and the results on
Ozsvath-Szabo invariants of fiber sums due to the author and Jabuka. In
addition, we give a calculation of the twisted Heegaard Floer homology of
circle bundles of "large" degree over Riemann surfaces.

Geometric Topology