A vanishing theorem for twisted Alexander polynomials with applications   to symplectic 4-manifolds
  In this paper we show that given any 3-manifold N and any non-fibered class in H^1(N;Z) there exists a representation such that the corresponding twisted Alexander polynomial is zero. This is obtained by extending earlier work of the authors, together with results of Agol and Wise on separability of 3-manifold groups. This result allows us to completely classify symplectic 4-manifolds with a free circle action, and to determine their symplectic cones. 
Stefan Friedl and Stefano Vidussi
math.GT math.SG