Solvmanifolds with integrable and non-integrable G_2 structures

I. Agricola, S. Chiossi, A. Fino

We show that a 7-dimensional non-compact Ricci-flat Riemannian manifold with Riemannian holonomy G_2 can admit non-integrable G_2 structures of type R + S^2_0(R^7) + R^7 in the sen…