Timeline for Strongly abnormal schemes
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| S Jun 17, 2019 at 22:01 | history | bounty ended | CommunityBot | ||
| S Jun 17, 2019 at 22:01 | history | notice removed | CommunityBot | ||
| Jun 10, 2019 at 18:21 | comment | added | Sándor Kovács | @KarlSchwede: right, of course, this idea only works if there are more than one points in the pre-image. Then again, the OP didn't say that the map cannot be an isomorphism.... :) | |
| Jun 10, 2019 at 3:19 | answer | added | Karl Schwede | timeline score: 2 | |
| Jun 10, 2019 at 3:08 | comment | added | Karl Schwede | @Sándor Kovács A quick comment. For 1), it should say something like every singular curve whose seminormalization is not normal. Cusps don't work. | |
| S Jun 9, 2019 at 20:12 | history | bounty started | CommunityBot | ||
| S Jun 9, 2019 at 20:12 | history | notice added | user141668 | Authoritative reference needed | |
| Jun 2, 2019 at 16:39 | comment | added | Sándor Kovács | OK, here is a cleaner version of those comments: 1) every singular proper curve is "abnormal": take the normalization and for each singular point throw away all but one of the pre-images. The remaining curve is affine and the morphism is bijective. 2) If homeomorphism is meant in the Zariski topology, then any two curves are homeomorphic and any bijective morphism between curves is a homeomorphism. And then any singular proper curve is "strongly abnormal". | |
| Jun 2, 2019 at 16:37 | comment | added | Sándor Kovács | That was a response to @kartop_man's comment. I am not saying that it needs to be downvoted, just that that might be the reason that some people did it. May be "makes no sense at all" was a little too much, sorry for that. | |
| Jun 2, 2019 at 10:15 | comment | added | user74900 | @SándorKovács What do you mean, makes no sense at all? Are there no examples in higher dimensions? I don't think this question was badly formulated or something to deserve downvotes. The post defined its terms, some people may dislike these definitions on aesthetical grounds. That is not a valid reason to downvote probably. | |
| Jun 2, 2019 at 6:47 | comment | added | user74900 | It is entirely possible the OP meant nodal cubic, see mathoverflow.net/a/330544/74900 | |
| Jun 1, 2019 at 20:16 | comment | added | user140765 | why the down-votes? | |
| Jun 1, 2019 at 16:51 | comment | added | YCor | Probably related: meta.mathoverflow.net/questions/4200/flood-of-new-users | |
| Jun 1, 2019 at 16:49 | history | edited | YCor |
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| Jun 1, 2019 at 16:15 | review | First posts | |||
| Jun 1, 2019 at 16:16 | |||||
| Jun 1, 2019 at 16:15 | history | asked | user141356 | CC BY-SA 4.0 |