The Alexander polynomial as a universal invariant

I will explain an interpretation of the Alexander polynomial as a universal invariant of long knots associated to the complex Hopf algebra of regular functions on the affine linear algebraic group of complex invertible upper triangular 2-by-2 matrices of the form
$$ \left(
\begin{array}{cc} a & b \\ 0 & 1 \end{array}
\right). $$

Preprint: arXiv:2007.11036