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Tim Campion
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Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold which is of type $n$ (i.e. a closed manifold $X$ such that $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime after $p$)-localization?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).Notes:

  • Recall that a finite CW complex $X$ is said to be of type $n$ if $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime $p$.

  • Recall the thick subcategory theorem tells us that for every $n$ (and every $p$) there exists a finite CW complex which is of type $n$ after $p$-localization, and conversely that every finite CW complex is of type $n$ for some $n$ after $p$-localization. The question is whether "finite CW complex" can be upgraded to "closed manifold".

  • When $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing, and $K(0) = H\mathbb Q$).

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold of type $n$ (i.e. a closed manifold $X$ such that $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime $p$)?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold which is of type $n$ after $p$-localization?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

Notes:

  • Recall that a finite CW complex $X$ is said to be of type $n$ if $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime $p$.

  • Recall the thick subcategory theorem tells us that for every $n$ (and every $p$) there exists a finite CW complex which is of type $n$ after $p$-localization, and conversely that every finite CW complex is of type $n$ for some $n$ after $p$-localization. The question is whether "finite CW complex" can be upgraded to "closed manifold".

  • When $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing, and $K(0) = H\mathbb Q$).

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Tim Campion
  • 64k
  • 13
  • 143
  • 384

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold of type $n$ (i.e. a closed manifold $X$ such that $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime $p$)?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold of type $n$?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold of type $n$ (i.e. a closed manifold $X$ such that $\widetilde{K(n)}_\ast X \neq 0$ but $\widetilde{K(m)}_\ast X = 0$ for $m < n$, where $K(n)$ is the $n$th Morava $K$-theory at the prime $p$)?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).

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Tim Campion
  • 64k
  • 13
  • 143
  • 384

For which $n$ does there exist a closed manifold of (chromatic) type $n$?

Let $p$ be a prime and $n \in \mathbb N$. Does there exist a closed manifold of type $n$?

When $n= 0$ the answer is yes. When $p = 2$ and $n = 1$ we can take $\mathbb R \mathbb P ^2$.

Other than that, I'm not sure.

It is worth noting that when $n \geq 1$, a closed manifold of type $n$ can't be orientable (since if it's orientable, then by Poincare duality its reduced rational homology is nonvanishing).