The tropical geometry of Hurwitz numbers

Video File: 
Abstract: 
Hurwitz theory, or the study of covers of the Riemann sphere, intertwines<br>representation theory, algebraic geometry, and combinatorics. I will give an<br>introduction to tropical geometry, which lies at the intersection of<br>geometry and combinatorics, by considering the manner in which it can answer<br>questions in Hurwitz theory. I will focus on the Hurwitz counting problem,<br>which tropical geometry re-envisions as a counting problem for certain<br>piecewise linear functions on finite graphs, and try to explain the<br>different ways in which these ideas can arise. I will use these ideas to<br>explain a beautiful piecewise polynomiality property of Hurwitz numbers.<br>Time permitting, I will discuss generalizations and analogues in other<br>settings. <br><br>** I will not assume any sophisticated algebraic geometry. Students are<br>particularly welcome to attend!
Subject: 
Category: 
Lecture Series / Conference / Course : 
Youtube-url: 
https://youtu.be/ZprKh5AXiBQ
Coordinator: 
Start Time: 
15:30
End Time: 
16:30
Date: 
Tuesday, September 25, 2018
Short Title: 
The tropical geometry of Hurwitz numbers