Locally conformal calibrated G_2-manifolds

We study conditions for which the mapping torus of a 6-manifold endowed with an SU(3)-structure is a locally conformal calibrated G2-manifold, that is, a 7-manifold endowed with a G2-structure φ such that dφ=−θ∧φ for a closed nonvanishing 1-form θ. Moreover, we show that if (M,φ) is a compact locally conformal calibrated G2-manifold with L_(θ#)φ=0, where θ# is the dual of θ with respect to the Riemannian metric g_φ induced by φ, then M is a fiber bundle over S^1 with a coupled SU(3)-manifold as fiber.