The next talk in the Greater Washington Topology Seminar is on **Friday, October 23 from 1pm to 2pm EDT and will be held virtually via Zoom. **

1. October 2, 2020: Louis H. Kauffman (University of Illinois at Chicago and Novosibirsk State University)

2. October 9, 2020: Charles Frohman (University of Iowa)

3. October 16, 2020: Thang T. Q. Lê (Georgia Institute of Technology)

4. **October 23, 2020: Pierrick Bousseau (ETH Zurich)**

5. October 30, 2020: Micah Chrisman (Ohio State University)

6. November 13, 2020: Boštjan Gabrovšek (University of Ljubljana)

7. November 20, 2020: Razvan Gelca (Texas Tech University)

8. December 4, 2020: Helen Wong (Claremont McKenna College)

Speaker: Pierrick Bousseau

Title: The skein algebra of the 4-punctured sphere from curve counting

Abstract: The Kauffman bracket skein algebra is a quantization of the algebra of regular functions on the SL_2 character variety of a topological surface. I will explain how to realize the skein algebra of the 4-punctured sphere as the output of a mirror symmetry construction based on higher genus Gromov-Witten invariants of a log Calabi-Yau cubic surface. This leads to a proof of a previously conjectured positivity property of the bracelets bases of the skein algebras of the 4-punctured sphere and of the 1-punctured torus.

The Zoom information is listed below (it is the same as last time):

Topic: GW Topology Seminar

Join Zoom Meeting

Meeting ID: 951 840 9059

Password: The last name of the Fields Medalist famous for his work on von Neumann algebras and knot polynomials; first letter capitalized.