Timeline for When are isotrivial families split by a finite base-change?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
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| Jul 25, 2014 at 12:44 | comment | added | Jason Starr | At least in characteristic 0, I think it should be fine for all non-uniruled varieties. Of course everything is fine when the automorphism group is finite (or can be "naturally" reduced to a finite group). That leaves varieties whose automorphism group contains a positive-dimensional (connected) linear group. But all such groups are (geometrically) rational. Thus the orbits are unirational. So the variety is uniruled. | |
| Jul 25, 2014 at 6:54 | comment | added | abx | It seems likely, but I am not completely sure: you might get into trouble with automorphisms acting trivially in cohomology, for instance. | |
| Jul 24, 2014 at 20:53 | comment | added | Vesselin Dimitrov | Thank you! It seems that the same should hold for smooth isotrivial families of varieties of non-negative Kodaira dimension? | |
| Jul 24, 2014 at 20:07 | vote | accept | Vesselin Dimitrov | ||
| Jul 24, 2014 at 19:51 | history | answered | abx | CC BY-SA 3.0 |