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Timeline for Torsion in Deligne cohomology

Current License: CC BY-SA 3.0

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May 3, 2018 at 22:28 history notice removed user95222
May 2, 2018 at 22:25 history notice added user95222 Reward existing answer
S Apr 23, 2018 at 16:06 history bounty ended CommunityBot
S Apr 23, 2018 at 16:06 history notice removed user119470
S Apr 22, 2018 at 16:06 history bounty started CommunityBot
S Apr 22, 2018 at 16:06 history notice added user119470 Reward existing answer
Feb 8, 2018 at 5:38 vote accept CommunityBot
Feb 8, 2018 at 4:14 answer added user87684 timeline score: 4
Feb 8, 2018 at 3:10 comment added user92332 As you note, $H^i_{\mathcal{D}}(X,\mathbf{Z}(p))$ contains a copy of a quotient of a $\mathbf{Q}$-vector space, hence lots of divisible elements. If you ask yourself the question whether $J^{i,p}(X/\mathbf{C})$ contains torsion divisible elements, then the answer is yes as soon as $H^i(X,\mathbf{Z}(p))$ is not contained in $F^pH^i_{\rm dR}(X/\mathbf{C})$. If so, then $J^{i,p}(X/\mathbf{C})$ is a $\mathbf{Q}$-vector space, hence torsion free. It typically never happens that $H^i(X,\mathbf{Z}(p))\subset F^pH^i_{\rm dR}(X/\mathbf{C})$, so usually $J^{i,p}(X/\mathbf{C})_{\rm tor}$ has div elements
Feb 8, 2018 at 2:52 history edited user113393 CC BY-SA 3.0
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Feb 8, 2018 at 1:25 history edited user113393 CC BY-SA 3.0
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Feb 7, 2018 at 20:40 history edited user113393 CC BY-SA 3.0
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Feb 7, 2018 at 19:40 comment added K.K. After the edit, $j = p$ in my comment above.
Feb 7, 2018 at 18:33 history edited user113393
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Feb 7, 2018 at 18:21 history edited user113393 CC BY-SA 3.0
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Feb 7, 2018 at 18:18 comment added K.K. The Deligne cohomology group with $i = 2$ and $j=1$ is isomorphic to the Picard group of $X$, so, in this case, the answer to your second question also depends on $X$.
Feb 7, 2018 at 17:58 history asked user113393 CC BY-SA 3.0