On the number of components of twisted torus links

Abstract

Twisted torus links $T(p,q;r,s)$ generalize torus links by introducing $s$ additional twists on $r$ adjacent strands of the torus link $T(p,q)$. It is well known that the number of components of a torus link $T(p,q)$ is given by the greatest common divisor of $p$ and $q$. However, determining the number of components of twisted torus links is not as straightforward based solely on their parameters. In this work, we present a Euclidean algorithm-like procedure for computing the number of components of twisted torus links based on their parameters. As a result, we show that the number of components of a twisted torus link $T(p,q;r,s)$ is a multiple of $\gcd (p,q,r,s)$, and in particular, $T(p,q;r,s)$ is a knot only if $\gcd (p,q,r,s)=1$. We also use our algorithm to prove several conjectures related to the number of components in twisted torus links.

10 pages, 5 figures; comments are welcome