We study the Ricci flow on a closed manifold and finite time interval
on
which certain integral curvature energies are finite. We prove that in dimension four,
such flow converges to a smooth Riemannian manifold except for finitely many
orbifold singularities. We also show that in higher dimensions, the same
assertions hold for a closed Ricci flow satisfying another condition of integral
curvature bounds. Moreover, we show that such flows can be extended over
by an
orbifold Ricci flow.
