Locally conformal calibrated G2-manifolds

We study conditions for which the mapping torus of a 6-manifold endowed with an SU(3)-structure is a locally conformal calibrated G(2)-manifold, that is, a 7-manifold endowed with a G(2)-structure phi such that d(phi) = -theta Lambda phi for a closed nonvanishing 1-form theta. Moreover, we showthat if (M, phi) is a compact locally conformal calibratedG(2)-manifold with L-theta#phi = 0, where theta(#) is the dual of theta with respect to the Riemannian metric g(phi) induced by phi, then M is a fiber bundle over S-1 with a coupled SU(3)-manifold as fiber.