Hyperbolic families, and Counting Colourings
- Series
- Combinatorics Seminar
- Time
- Friday, November 10, 2023 - 15:15 for 1 hour (actually 50 minutes)
- Location
- Skiles 308
- Speaker
- Evelyne Smith-Roberge – Georgia Tech – esmithroberge3@gatech.edu
Langhede and Thomassen conjectured in 2020 that there exists a positive constant c such that every planar graph G with 5-correspondence assignment (L,M) has at least 2^{c v(G)} distinct (L,M)-colourings. I will discuss a proof of this conjecture (which relies on the hyperbolicity of a certain family of graphs), a generalization of this result to some other embedded graphs (again, relying on a hyperbolicity theorem), and a few open problems in the area. Everything presented is joint work with Luke Postle.