 Seifert surface

A Seifert surface for an oriented knot $K$ is a compact connected oriented surface $F\subset S^3$ with oriented boundary $\partial F=K$.

A Seifert surface is a surface used in the field of topology, particularly in the study of knots and links in three-dimensional space. Named after Herbert Seifert, these surfaces are oriented surfaces that are bounded by a given link in the three-dimensional sphere \( S^3 \). The key properties and characteristics of Seifert surfaces include: 1. **Boundary**: The boundary of a Seifert surface is a link in \( S^3 \).