Timeline for Positivity of the intersection form [closed]
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| S Oct 29, 2022 at 16:17 | history | locked | CommunityBot | ||
| S Oct 29, 2022 at 16:17 | history | closed |
abx Ryan Budney Sebastian Goette user44191 Friedrich Knop |
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| Oct 28, 2022 at 4:52 | review | Close votes | |||
| Oct 29, 2022 at 16:17 | |||||
| Oct 28, 2022 at 4:35 | comment | added | abx | Yes. There is an $a$ in $H_2(M,\mathbb{R})$ with $I(a,a)>0$, then any $b$ in $H_2(M,\mathbb{Q})$ sufficiently close to $a$ will have $I(b,b)>0$, and some multiple of $b$ will be in $H_2(M,\mathbb{Z})$. Note that this is a general fact about quadratic forms, nothing particular about the intersection form. | |
| Oct 28, 2022 at 1:13 | history | asked | Adterram | CC BY-SA 4.0 |