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Question

Math 6510 • Differentiable Manifolds

Spring 2019 • Question 9

Fix integers \(n\ge 1\) and \(m\ge 1\).

  1. Construct a connected space \(X\) such that \[ \widetilde {H}_r(X;\mathbb {Z})= \begin {cases} 0 & \text {if } r\ne n,\\ \mathbb {Z}/m & \text {if } r=n. \end {cases} \] (Here \(\widetilde {H}\) denotes reduced homology.)
  2. For any connected space \(X\) satisfying the conclusion of part (a), compute the groups \(H_r(X;\mathbb {Z}/2)\) for all \(r\ge 0\).

Raw LaTeX

Fix integers \(n\ge1\) and \(m\ge1\).

\begin{enumerate}
\item[(a)] Construct a connected space \(X\) such that
\[
  \widetilde{H}_r(X;\Z)=
  \begin{cases}
    0 & \text{if } r\ne n,\\
    \Z/m & \text{if } r=n.
  \end{cases}
\]
(Here \(\widetilde{H}\) denotes reduced homology.)
\item[(b)] For any connected space \(X\) satisfying the conclusion of part (a),
compute the groups \(H_r(X;\Z/2)\) for all \(r\ge0\).
\end{enumerate}