Past Seminars- Differential Geometry

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  • Matthew Gursky
    Tue Mar 13, 2018
    3:00 pm
    In this talk I will describe a singular boundary value problem for Einstein metrics.  This problem arises in the Fefferman-Graham theory of conformal invariants, and in the AdS/CFT correspondence.   After giving a brief overview of some important results and examples, I will present a recent construction of boundary data which cannot...
  • Henri Roesch
    Tue Mar 6, 2018
    4:00 pm
    In the first half of the talk, we introduce a new quasi-local mass with interesting properties along null flows off of a 2-sphere in spacetime or, equivalently, foliations of a null cone. We also show how certain, fairly generic, convexity assumptions on the null cone allows for a proof of the Penrose Conjecture. On the Black Hole Horizon, we find...
  • Adam Jacob
    Tue Feb 27, 2018
    4:00 pm
    The study of tangent cones in geometric analysis is an important tool in understanding the structure at a singular point of a geometric equation. In this talk I will discuss how to uniquely identify the tangent cone of a Yang-Mills connection with isolated singularity in the complex setting, given an initial assumption on the complex structure of...
  • Tue Feb 20, 2018
    3:00 pm
    Speaker #1: Renato Bettiol (University of Pennsylvania)  Title:  A Weitzenbock viewpoint on sectional curvature and application Abstract:  In this talk, I will describe a new algebraic characterization of sectional curvature bounds that only involves curvature terms in the Weitzenboeck formulae for symmetric tensors. This...
  • Dan Knopf
    Tue Feb 13, 2018
    4:00 pm
    We describe Riemannian (non-Kahler) Ricci flow solutions that develop finite-time Type-I singularities whose parabolic dilations converge to a shrinking Kahler–Ricci soliton singularity model. More specifically, the singularity model for these solutions is the “blowdown soliton” discovered in 2003 by Feldman, Ilmanen, and the...
  • Norman Zergaenge
    Tue Jan 30, 2018
    4:00 pm
    A key challenge in Riemannian geometry is to find ``best" metrics on compact manifolds. To construct such metrics explicitly one is interested to know if approximation sequences contain subsequences that converge in some sense to a limit manifold. In this talk we will present convergence results of sequences of closed Riemannian 4-manifolds...
    Sat Jan 27, 2018 - Sun Jan 28, 2018
    11:00 am
    Conference website: Please register at the conference website if planning to attend.