## Organizer(s) | Paul Feehan, Manousos Maridakis, Natasa Sesum | ## Archive |

## Past Talks

## Tuesday, March 7th |

## Siao-Hao Guo , |

## "Analysis of Velázquez's solution to the mean curvature flow with a type II singularity" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract: J.J.L. Velázquez in 1994 used the degree theory to show that there is a perturbation of Simons' cone, starting from which the mean curvature flow develops a type II singularity at the origin. He also showed that under a proper time-dependent rescaling of the solution around the origin, the rescaled flow converges in the C^0 sense to a minimal hypersurface which is tangent to Simons' cone at infi nity. In this talk, we will present that the rescaled flow actually converges locally smoothly to the minimal hypersurface, which appears to be the singularity model of the type II singularity. In addition, we will show that the mean curvature of the solution blows up near the origin at a rate which is smaller than that of the second fundamental form.
This is a joint work with N. Sesum. |

## Tuesday, February 21st |

## Bing Wang , |

## "The extension problem of the mean curvature flow (I)" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract: We show that the mean curvature blows up at the first finite singular time for a closed smooth embedded mean curvature flow in R^3.
This is a joint work with H.Z. Li. |

## Tuesday, February 14th |

## Kyeongsu Choi , |

## "Free boundary problems on the Gauss curvature flow" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract: We will discuss about the optimal $C^{1,frac{1}{n-1}}$ regularity of the Gauss curvature flow with a flat side and
the $C^{infty}$ regularity of its free boundary, namely the boundary of the flat side. We establish estimates by
applying the maximum principle for chart independent geometric quantities. |

## Tuesday, February 7th |

## Xiaoliu Wang , |

## "Nonlocal Curvature Flows" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract: In this talk, some nonlocal planar cuvature flows will be introduced, including the area-preserving flow and the length-preserving one, etc. The locally convex initial curve could be embedded or immersed. Some sharp conditions on immersed initial curves are established to yield the singularity of the flow at a finte time. In addition, the symmetry of curves are found to play an important role in the flow's evolution. |

## Tuesday, January 31st |

## Siao-Hao Guo, |

## "Analysis of Velázquez's solution to the mean curvature flow with a type II singularity" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract:
J.J.L. Velázquez in 1994 used the degree theory to show that there is a perturbation of Simons' cone, starting from which the mean curvature flow develops a type II singularity at the origin. He also showed that under a proper time-dependent rescaling of the solution around the origin, the rescaled flow converges in the C^0 sense to a minimal hypersurface which is tangent to Simons' cone at infi nity. In this talk, we will present that the rescaled flow actually converges locally smoothly to the minimal hypersurface, which appears to be the singularity model of the type II singularity. In addition, we will show that the mean curvature of the solution blows up near the origin at a rate which is smaller than that of the second fundamental form.
This is a joint work with N. Sesum. |

## Tuesday, January 24th |

Special Geometric Analysis Seminar |

## Professor Lu Wang, |

## " Surfaces of Low Entropy" |

Time: 3:00 PM |

Location: Hill 705 |

Abstract: The entropy of a (hyper)-surface is given by the supremum over all Gaussian integrals with varying centers and scales. It is a geometric invariant that measures complexity of the surface. This quantity is introduced by Colding and Minicozzi to understand the singularity formation of mean curvature flow of surfaces. In this talk, I will discuss several results which show that closed surfaces that have small entropy are simple in various senses.
This is joint with Jacob Bernstein. |