With reference to Exercise 10, the torus X can be mapped onto its circle b (which is
Question:
With reference to Exercise 10, the torus X can be mapped onto its circle b (which is homeomorphic to S1) by a variety of maps. For each such map f : X → b given below, describe the homomorphism f*n : Hn(X) → Hn(b) for n = 0, 1, and 2, by describing the image of generators of Hn(X) as in Exercise 10.
a. f: X → b given by f((θ, ∅)) = (θ, 0)
b. f: X → b given by f((0, ∅)) = (2θ, 0)
Data from Exercises 10
Every point P on a regular torus X can be described by means of two angles θ and ∅, as shown in Fig. 43.16. That is, we can associate coordinates (θ, ∅) with P. For each of the mappings f of the torus X onto itself given below, describe the induced map f*n of Hn(X) into Hn(X) for n = 0, 1, and 2, by finding the images of the generators for Hn(X) described in Example 42.12. Interpret these group homomorphisms geometrically as we did in Example 43.9.
Data from Figure 43.16
Step by Step Answer: