The mean curvature flow is an evolution process under which a submanifold deforms in the direction of its mean curvature vector. The hypersurface case has been much studied since the eighties. Recently, several theorems on regularity, global existence and convergence of the flow in various ambient spaces and codimensions were proved. We shall explain the results obtained as well as the techniques involved. The potential applications in symplectic topology and mirror symmetry will also be discussed.

We study the uniqueness of minimal submanifolds and the stability of the mean curvature flow in several well-known model spaces of manifolds of special holonomy. These include the Stenzel metric on the cotangent bundle of spheres, the Calabi metric on the cotangent bundle of complex projective spaces, and the Bryant--Salamon metrics on vector bundles over certain Einstein manifolds. In particular, we show that the zero sections, as calibrated submanifolds with respect to their respective ambient metrics, are unique among compact minimal submanifolds and are dynamically stable under the mean curvature flow. The proof relies on intricate interconnections of the Ricci flatness of the ambient space and the extrinsic geometry of the calibrated submanifolds.

In this article we introduce higher order Bergman functions for bounded complete Reinhardt domains in a variety with possi- bly isolated singularities. These Bergman functions are invariant under biholomorhic maps. We use Bergman functions to deter- mine all the biholomorhic maps between two such domains. As a result, we can construct an infinite family of numerical invari- ants from the Bergman functions for such  domains in An variety (x, y, z) ∈ C3 : xy = zn+1 . These infinite family of numerical invariants are actually a complete set of invariants for either the set of all bounded strictly pseudoconvex complete Reinhardt domain in An variety or the set of all bounded pseudoconvex complete Reinhardt domains with real analytic boundaries in An variety. In particular the moduli space of these domains in An variety is constructed explicitly as the image of this complete family of numerical invariants. It is well known that An variety is the quo- tient of cyclic group of order n + 1 on C2. We prove that the moduli space of bounded complete Reinhardt domains in An vari- ety coincides with the moduli space of the corresponding bounded complete Reinhardt domains in C2. Since our complete family of numerical invariants are computable, we have solved the biholo- morphically equivalent problem for large family of domains in C2.

The authors proved in [5] that in a complete, connected, and simply connected Riemannian manifold, the volume of the intersection of two small geodesic balls depends only on the distance between the centers and the radii if and only if the space is harmonic. In this paper, we show that this proposition remains true, if the condition is restricted to balls of equal radii.

We nd a one-parameter family of coordinates f hgh2R which is a deformation of Penner's simplicial coordinate of the decorated Teichmuller space of an ideally triangulated punctured surface (S; T) of negative Euler characteristic. If h > 0, the decorated Teichmuller space in the h coordinate becomes an explicit convex polytope P(T) independent of h, and if h < 0, the decorated Teichmuller space becomes an explicit bounded convex polytope Ph(T) so that Ph(T)  Ph0 (T) if h < h0. As a consequence, Bowditch-Epstein and Penner's cell decomposition of the decorated Teichmuller space is reproduced.