Suppose that $X$ is a torus bundle over a closed surface with homologically essential fibers. Let $X_K$ be the manifold obtained by Fintushel--Stern knot surgery on a fiber using a knot $K\subset S^3$. We prove that $X_K$ has a symplectic structure if and only if $K$ is a fibered knot. The proof uses Seiberg--Witten theory and a result of Friedl--Vidussi on twisted Alexander polynomials.
Geometrically simply connected 4-manifolds and stable cohomotopy Seiberg-Witten invariants
Twisted Alexander polynomials and symplectic structures
Giroux correspondence, confoliations, and symplectic structures on S^1 x M
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