Rotation numbers for curves on a torus
β Scribed by Hitoe Tanio; Osamu Kobayashi
- Book ID
- 104642804
- Publisher
- Springer
- Year
- 1996
- Tongue
- English
- Weight
- 454 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0046-5755
No coin nor oath required. For personal study only.
β¦ Synopsis
We define a regular homotopy invariant of closed curves on a surface, and give a formula for the rotation number of closed curves on toms, which is analogous to the Whitney formula for planar curves. As an application, we show a necessary condition for a Gauss word to be realized on toms.
π SIMILAR VOLUMES
We show that if \(G\) is a graph embedded on the torus \(S\) and each nonnullhomotopic closed curve on \(S\) intersects \(G\) at least \(r\) times, then \(G\) contains at least \(\left\lfloor\frac{3}{4} r\right\rfloor\) pairwise disjoint nonnullhomotopic circuits. The factor \(\frac{3}{4}\) is best