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2022.11.19 Tecent meeting ID: 192-351-356 (GTM+8) Beijing Time Code:1119
Topology seminar in East China
List of speakers: Lin Jianfeng, Lv Zhi, Ma jiming, Yang Wenyuan and Zhang Qiang.
2022.11.05 Tencent meeting ID: 714-879-662 (GMT+8) Beijing Time Code:1105
11:00-12:00 Stavros Garoufalidis Counting incompressible surfaces in 3-manifolds
2020.10.17 Tencent meeting ID: 570 925 367 (GMT+8）Beijing Time
09:00-10:00 Wenyuan Yang (BICMR) Croke-Kleiner admissible groups: Property (QT) and quasiconvexity
10:20- 11:20 Xiao Wang (Jilin University) On Yang-Baxter Homology
2020.9.26 Tencent meeting ID: 529881266 (GMT+8）Beijing Time
09:00-10:00 Qiang Zhang (Xi'an Jiaotong University) Fixed point indices and fixed words at infinity of selfmaps of graphs
2020.7.3 Zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
15:00-16:00 Faze Zhang (Northeast Normal University) Angle Structures on hyperbolic 3-manifolds.
2020.6.20 Zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
8:30-9:30 Harry Hyungryul Baik (KAIST) Title: Normal generators for mapping class groups are abundant in the fibered cone
Abstract: We show that for almost all primitive integral cohomology classes in the fibered cone of a closed fibered hyperbolic 3-manifold, the monodromy normally generates the mapping class group of the fiber. The key idea of the proof is to use Fried’s theory of suspension flow and dynamic blow-up of Mosher. If the time permits, we also discuss the non-existence of the analog of Fried’s continuous extension of the normalized entropy over the fibered face in the case of asymptotic translation lengths on the curve complex. This talk is based on joint work with Eiko Kin, Hyunshik Shin and Chenxi Wu.
10:00-11:00 Yi Ni (Caltech) Title:Thurston norm minimizing Seifert surfaces
Abstract: Let K be a null-homologous knot in a closed 3-manifold Y, and F be a Seifert surface. One can cap off the boundary of F with a disk in the zero surgery on K to get a closed surface F_0.
If we know that F is Thurston norm minimizing, we can ask whether F_0 is also Thurston norm minimizing. A classical theorem of Gabai says that the answer is Yes when Y is the 3-sphere. Gabai's theorem can be generalized to many other 3-manifolds using Heegaard Floer homology. In this talk, we will discuss a sufficient condition for F_0 to be Thurston norm minimizing which relates this property to the 4-genus of the knot.
14:00-15:00 Hongyu Wang(Yangzhou University) Title: On isoperimetric inequality of finitely presented groups
Abstract: In this talk, we discuss a radial isoperimetric inequality and it's application in manifold topology.
2020.6.13 Zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
08:30-10:00 Hongbin Sun(Rutgers University) Title: Subgroup separability and subgroup distortion of 3-manifold groups
Abstract: For a (finitely generated) subgroup of a (finitely generated) group, we will consider two properties of this subgroup: the separability of this group and its subgroup distortion. The separability of a subgroup measures whether the property of an element not lying in this subgroup is visible by taking some finite quotient. We will give a characterization on whether a subgroup of a 3-manifold group is separable. The subgroup distortion compares the intrinsic and extrinsic geometry of a subgroup. For an arbitrary subgroup of a 3-manifold group, we prove that the subgroup distortion can only be linear, quadratic, exponential and double exponential. It turns out the subgroup separability and subgroup distortion are closed related for subgroups of 3-manifold groups. The subgroup distortion part is joint work with Hoang Nguyen (at BICMR).
10:20-11:20 Ying Zhang (Soochow University) Title：最对称双曲环面的测地线长度比较
2020.6.6 zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
14:00-15:00 Jiajun Wang (Peking University) Title: Heegaard floer homology and fundamental groups.
Abstract: The geometrization theorem implies that the fundamental group of a 3-manifold determines the 3-manifold, except the lens space. However, the direct relation between Floer homology and the fundamental group remains open. In this talk, we will talk about how to read the floer homology from its fundamental group for certain knots.
2020.5.30 Zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
8:00-9:30 TaoLi (Boston College) Title: Berge conjectures for tunnel number one knots
14:30-15:50 Jiming Ma (Fudan University) Title:复双曲三角群无穷远处的三维流形
16:00-17:20 Tian Yang（Texas A&M University) Title: Some recent progress on the volume conjecture for Reshetikhin-Turaev invariants
2020.5.23 Zoom Online ID: 274 175 4144 PW: 930643 （GMT+8) Beijing time
13:40-14:40 Ping Li (Tongji University) Title: Curvature and Chern number inequalities
14:50-15:50 Zhi Lv (Fudan University) Title: Equivariant unitary bordism for torus groups
16:00-17:00 Zhiyun Cheng (Beijing Normal Univeristy) Title: Region crossing change on surfaces