Long-time existence of the Laplacian flow with Weyl tensor
We establish integral extension criteria for the Laplacian flow of closed $G_2$-structures on compact $7$-dimensional manifolds $M$. Assuming a uniform lower bound for the scalar curvature, we prove that a finite-time solution extends smoothly whenever the spatial $L^p$ norm of the $77$-dimensional Weyl component $W_{7...