Timeline for A closed manifold with a subset with the same ring cohomology
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Feb 1, 2014 at 6:59 | vote | accept | Ali Taghavi | ||
| Jan 31, 2014 at 5:29 | comment | added | Alex Degtyarev | In the non orientable case, a similar argument shows that the induced homomorphism $H_n(A;\mathbb{Z}_2)\to H_n(M;\mathbb{Z}_2)$ is trivial. On the other hand, if the inclusion induced an isomorphism with $\mathbb{Z}$ coefficients, it would also be an isomorphism with any coefficients (universal coefficient formula). | |
| Jan 30, 2014 at 23:22 | comment | added | Neil Strickland | This does not make much difference. I have modified the argument. | |
| Jan 30, 2014 at 23:22 | history | edited | Neil Strickland | CC BY-SA 3.0 |
Modified to deal with non-closed $A$
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| Jan 30, 2014 at 22:58 | comment | added | Ali Taghavi | I did not assume that $A$ is closed(It is possible that $A$ is dense. so we can not choose the open disc $U$. | |
| Jan 30, 2014 at 22:54 | history | answered | Neil Strickland | CC BY-SA 3.0 |