Index

This illustrates the fact that the projection from the helix to
the annulus is a covering map. For each sufficiently small patch
in the annulus, the preimage in the helix is a disjoint union of a
discrete set of homeomorphic patches. This is essentially the
same as the behaviour of the exponential map $\exp\colon B\to A$,
where
\begin{align*}
B &= \{ x + iy \in \mathbb{C} \;|\; 1 < x < 2 \} \\
A &= \{ z \in \mathbb{C} \;|\; e < |z| < e^2 \}.
\end{align*}

You can click and drag the patch, or use the mouse wheel to change the size of the patch.

You can click and drag the patch, or use the mouse wheel to change the size of the patch.