## Seminar Categories

- Uncategorized (1)
- Applied and Computational Mathematics Seminar (1)
- Climate Seminar (7)
- Colloquium (5)
- Combinatorics Seminar (2)
- Differential Geometry and Symplectic Topology Seminar (1)
- First Year Seminar (3)
- IMA Data Science Lab Seminar (2)
- Lie Theory Seminar (1)
- Math Physics Seminar (2)
- Ordway Lecture Series (5)
- PDE Seminar (1)
- Probability Seminar (2)

## Current Series

Thu Sep 20 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Monotonicity formulas and Type I singularities Huaidong Cao, Ordway Visitor, Lehigh University In this talk we shall introduce Huisken's monotonicity formula for the mean curvature flow and Perelman's monotonicity formulas for the Ricci flow. We shall discuss their applications, including the role they play in studying Type-I singularities of the flows. |

Thu Sep 27 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Second variation of Perelman's entropy and stability of Ricci solitons Huaidong Cao, Ordway Visitor, Lehigh University Einstein metrics are critical points of the well-known classical Hilbert action |

Thu Oct 04 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Stability of Ricci solitons Huaidong Cao - Ordway Visitor, Lehigh University In this talk we continue our discussion of the previous week on stability of |

Fri Oct 19 |
## Differential Geometry and Symplectic Topology Seminar2:30pm - Vincent Hall 6The Smooth 4-dimensional Poincare Conjecture and Dehn surgery on links Alex Zupan, University of Nebraska The smooth version of the 4-dimensional Poincare Conjecture (S4PC) states that every homotopy 4-sphere is diffeomorphic to the standard 4-sphere. One way to attack the S4PC is to examine a restricted class of 4-manifolds. For example, Gabai's proof of Property R implies that every homotopy 4-sphere built with one 2-handle and one 3-handle is standard. In this talk, we consider homotopy 4-spheres X built with two 2-handles and two 3-handles, which are uniquely determined by the attaching link L for the 2-handles in the 3-sphere. We prove that if one of the components of L is the connected sum of a torus knot T(p,2) and its mirror (a generalized square knot), then X is diffeomorphic to the standard 4-sphere. This is joint work with Jeffrey Meier. |

Thu Dec 06 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Enumerative geometry: old and new Felix Janda, University of Michigan For as long as people have studied geometry, they have counted In this talk, I will show how to solve several classical counting |

Thu Dec 20 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Projective Geometry, Complex Hyperbolic Space, and Geometric Transitions Steve Trettel, UC Santa Barbara The natural analog of Teichmuller theory for hyperbolic manifolds in dimension 3 or greater is trivialized by Mostow Rigidity, so mathematicians have worked to understand more general deformations. Two well studied examples, convex real projective structures and complex hyperbolic structures, have been investigated extensively and provide independently developed deformation theories. Here we will discuss a surprising connection between the these, and construct a one parameter family of geometries deforming complex hyperbolic space into a new geometry built out of real projective space and its dual. This connects the aforementioned deformation theories and provides geometric motivation for a representation-theoretic observation of Cooper, Long, and Thistlethwaite |

Tue Apr 23 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Self-homeomorphisms of reducible 3-manifolds and applications in topology, geometry and dynamics. Christoforos Neofytidis, University of Geneva We recall the self-homeomorphisms of a closed oriented reducible 3-manifold. Using this description, we discuss various problems in low-dimensional topology and dynamics, such as the existence of Anosov tori in 3-manifolds (joint work with Shicheng Wang), the simplicial volume of mapping tori of 3-manifolds (joint work Michelle Bucher) and the virtual Betti numbers of mapping tori of 3-manifolds. |

Thu Apr 25 |
## Differential Geometry and Symplectic Topology Seminar1:25pm - Vincent Hall 570Harmonic surfaces and simple loops Vlad Markovic - Ordway Visitor, Caltech |