Short-time behaviour of a modified Laplacian coflow of G2-structures

We modify the Laplacian coflow of co-closed G2-structures - ddtψ=Δψ where ψ is the closed dual 4-form of a G2-structure φ. The modified flow is now weakly parabolic in the direction of closed forms up to diffeomorphisms. We then prove short time existence and uniqueness of solutions to the modified flow.