Lagrangian mean curvature flow in the complex projective plane
In this thesis, we study Lagrangian mean curvature flow of monotone Lagrangians in two different settings, finding interesting and contrasting behaviour in each case. First, we study the self-shrinking Clifford torus in C2. On the one hand, we find a family of Ck-small Hamiltonian deformations that force type II singularities to form. On the other hand, we find that any Hamiltonian deformation restricted to the unit sphere flows back to the self-shrinking Clifford torus after rescaling. Second, we study Lagrangian mean curvature flow in Kähler–Einstein manifolds with positive Einstein constant. We show that monotone Lagrangians do not attain type I singularities under mean curvature flow, an analogue of a result of Wang [49]. Next, we investigate Lagrangian mean curvature flow of Vianna’s exotic monotone tori ([47], [48]) in CP2. We define an (S1 × Z2)-equivariance, and we prove a Thomas–Yau-type result in this setting. We define a surgery procedure and show that any equivariant monotone Lagrangian torus exists for all time under mean curvature flow with surgery, undergoing at most a finite number of surgeries before converging to a minimal Clifford torus. In particular, our result show that there does not exists a minimal equivariant Chekanov torus. Furthermore, we explicitly construct a monotone Clifford torus which has two finite-time singularities under mean curvature flow with surgery, becoming a Chekanov torus before eventually returning to become a Clifford torus again.