Timeline for Lefschetz hyperplane section theorem for intersection homology
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 30, 2017 at 21:09 | vote | accept | user45397 | ||
| Mar 29, 2017 at 21:03 | comment | added | Dan Petersen | Oh, I see. I thought the "usual" Lefschetz theorem had an assumption that $Y$ is smooth, but I see now that it's enough that the singular locus of $X$ is contained in $Y$. Yeah, then I agree with you. | |
| Mar 29, 2017 at 20:59 | comment | added | Mikhail Bondarko | I am just saying that if you replace the group $H^k(Y)$ in the Lefschetz theorem by the group $IH_k(Y)$ that is not isomorphic to it then you would get a wrong statement. However, it may happen that $H^k(Y)$ is always isomorphic to $IH_k(Y)$ the range in question. Anyway, the (current) argument of user45397 is not correct. | |
| Mar 29, 2017 at 20:34 | comment | added | Dan Petersen | I don't think this answers the question. I would've expected the answer to be "yes" and I don't really see an argument in your answer for why you think the isomorphism fails in general. | |
| Mar 29, 2017 at 12:16 | history | answered | Mikhail Bondarko | CC BY-SA 3.0 |