Pj. Olver et al., CLASSIFICATION AND UNIQUENESS OF INVARIANT GEOMETRIC FLOWS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 319(4), 1994, pp. 339-344
In this Note we classify flows invariant to subgroups of the projectiv
e group. We prove that the geometric heat flow is the simplest of all
possible flows. These results are based on the theory of differential
invariants and symmetry groups.