Holonomic and Legendrian parametrizations of knots

Abstract

Let $f:S^1\to R$ be a generic map. We may use $f$ to define a new map $\tilde{f}:S^1\to R^3$ by $\tilde{f}(t) = (-f(t),f'(t),-f''(t))$, and if $f$ is an embedding then the image of $\tilde{f}$ will be a knot. Knots defined by such parametrizations are called holonomic knots. They were introduced in 1997 by Vassiliev, who proved that every knot type can be represented by a holonomic knot. Our main result is that any two holonomic knots which represent the same knot type are isotopic in the space of holonomic knots. A second result emerges through the techniques used to prove the main result: strong and unexpected connections between the topology of knots and the algebraic solution to the conjugacy problem in the braid groups, via the work of Garside. We also discuss related parametrizations of Legendrian knots, and uncover connections between the concepts of holonomic and Legendrian parametrizations of knots.