2025/09/02 by Serraille, Baptiste, Stokić, Maksim · 1 citation
#53D10 #FOS: Mathematics #Symplectic Geometry (math.SG)
paper · doi:10.48550/arxiv.2509.02430
We prove that contact homeomorphisms preserve characteristic foliations on surfaces in contact 3-manifolds. More precisely, since the characteristic foliation is a singular 1-dimensional foliation, we show that singular points are mapped to singular points, and that the image of every 1-dimensional leaf is again a 1-dimensional leaf in the image surface. As a consequence, regular coisotropic surfaces are C0-rigid. In contrast, we show that contact convexity is C0-flexible by constructing a contact homeomorphism that sends a convex 2-torus to a non-convex one.