Ricci flow on surfaces along the standard lightcone in the -Minkowski spacetime
arXiv:2206.02621 · doi:10.1007/s00526-022-02415-0
Abstract
Identifying any conformally round metric on the -sphere with a unique cross section on the standard lightcone in the -Minkowski spacetime, we gain a new perspective on -Ricci flow on topological spheres. It turns out that in this setting, Ricci flow is equivalent to a null mean curvature flow first studied by Roesch--Scheuer along null hypersurfaces. Exploiting this equivalence, we can translate well-known results from -Ricci flow first proven by Hamilton into a full classification of the singularity models for null mean curvature flow in the Minkowski lightcone. Conversely, we obtain a new proof of Hamilton's classical result using only the maximum principle.