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Timeline for Unbounded acyclic resolutions

Current License: CC BY-SA 4.0

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Dec 15, 2022 at 15:34 history rollback Jeremy Rickard
Rollback to Revision 2
Dec 15, 2022 at 15:34 comment added Jeremy Rickard @NikolasKuhn Hmm, I thought I had a reason, but now I'm not so sure. I'll roll back to the previous version while I think about it.
Dec 15, 2022 at 15:05 comment added Nikolas Kuhn Could you explain the statements about why the truncations are the homotopy limits of their further truncations?
Dec 15, 2022 at 14:53 comment added Jeremy Rickard @R.vanDobbendeBruyn I think the proof that I've added shows that the extra hypotheses are sufficient.
Dec 15, 2022 at 14:52 history edited Jeremy Rickard CC BY-SA 4.0
Added a proof with extra hypotheses.
Dec 15, 2022 at 14:41 comment added Jeremy Rickard @R.vanDobbendeBruyn I think I have an answer to the question with the added hypotheses, which I will edit into my previous answer if it survives the writing process, in which case the question in your comment is probably moot.
Dec 15, 2022 at 14:23 comment added R. van Dobben de Bruyn P.S. I got a downvote on the question after the last edit (without a comment explaining, as usual). Do you think I should ask a different question instead with the extra hypothesis, given that your answer technically addresses the question as asked?
Dec 14, 2022 at 23:05 comment added R. van Dobben de Bruyn I have now added the hypothesis that $F$ preserves products, like you suggested. There was already a hint of this hypothesis in the holim argument in my question. (Surely we can't "French trick" our way out of this by adding extra hypotheses until the statement becomes tautological?)
Dec 14, 2022 at 22:18 comment added R. van Dobben de Bruyn Thanks for this example! My understanding here is that because $\mathbf{Mod}_A$ is AB4*, every complex $C^\bullet$ is the derived limit of its truncations $\tau_{\geq -p} C^\bullet$, so what goes wrong here is indeed preservation of (countable) products under $F$. But at the very least, the example shows that any positive result cannot be completely formal ― this is already a break with the bounded below case where no hypothesis is needed.
Dec 14, 2022 at 18:24 history edited Jeremy Rickard CC BY-SA 4.0
Too many $R$'s
Dec 14, 2022 at 18:10 history answered Jeremy Rickard CC BY-SA 4.0