 Mapping torus

The mapping torus of $f:F\to F$ isIf $f$ is a homeomorphism, the projection to the circle $S^1$ is a fiber bundle with fiber $F$. For a general continuous map, the mapping torus need not be a fiber bundle, but its homology still has the Wang sequence.

A **mapping torus** is a concept in topology, specifically in the study of fiber bundles and manifolds. It is a way to construct a new topological space from a given manifold and a continuous function defined on it. To describe a mapping torus formally, consider the following: 1. **Space**: Let \( M \) be a topological space (often a manifold) and let \( f: M \to M \) be a continuous map.