Timeline for Topology of Lefschetz pencil
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 11, 2023 at 17:49 | comment | added | Jason Starr | If you allow $X$ to be singular, then there exists a pair of families that have $X_t$ the same for all $t\neq 0$, but where $X_0$ is either a cuspidal rational curve (thus simply connected) or a smooth elliptic curve (not simply connected). | |
| Apr 11, 2023 at 17:15 | comment | added | Ben C | I do mean for $f$ to be proper and flat. @Angelo I was worried this might not be true if $X$ is not smooth. Is it still true? | |
| Apr 11, 2023 at 17:14 | history | edited | Ben C | CC BY-SA 4.0 |
added 7 characters in body
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| Apr 11, 2023 at 14:18 | comment | added | Jason Starr | @Angelo The OP should specify that $X$ is smooth and $f$ is proper, otherwise there are silly counterexamples. | |
| Apr 11, 2023 at 10:20 | comment | added | Angelo | $X$ is homotopy equivalent to $X_0$. See for example mathoverflow.net/questions/264940/… | |
| Apr 11, 2023 at 9:10 | history | asked | Ben C | CC BY-SA 4.0 |