Let \(X_p=D^4\cup _f S^3\) be the space obtained by attaching a 4-cell to the 3-sphere by an attaching map \(f:\partial D^4\to S^3\) of degree \(p\).
- Compute the singular homology of \(H_*(X_p;\mathbb {Z})\) and \(H_*(X_p\times X_q;\mathbb {Z})\) for any \((p,q)\) using the CW-complex cell structure.
- Find \(H_*(X_p\times X_q;\mathbb {Z})\) using the Künneth Theorem.