A lower bound on critical points of the electric potential of a knot

英文摘要：

Given a knot $K$ parametrized by $r: [0,2π] \to \mathbb{R}^3$, we can define the electric potential on its complement by $Φ(x) = \int_0^{2π} \frac{|r'(t)|}{|x - r(t)|}dt$. Physicists and knot theorists want to understand the critical points of the potential and their behavior. The tunneling number $t(K)$ of a knot is the smallest number of arcs one needs to add to a knot so the complement is a handlebody. We show the number of critical points of the potential is at least $2t(K) + 2$. The result is proven using Morse theory and stable manifold theory.