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Jan 21, 2018 at 20:53 vote accept Daniel Litt
Jan 21, 2018 at 20:53 answer added Daniel Litt timeline score: 4
Aug 22, 2015 at 16:35 answer added P.J timeline score: 0
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Aug 17, 2015 at 18:48 history edited Daniel Litt CC BY-SA 3.0
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Aug 16, 2015 at 19:00 history edited Daniel Litt CC BY-SA 3.0
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S Aug 12, 2015 at 17:20 history bounty started Daniel Litt
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Aug 12, 2015 at 17:18 history edited Daniel Litt CC BY-SA 3.0
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Aug 11, 2015 at 13:01 answer added pgraf timeline score: 6
Aug 10, 2015 at 19:21 comment added Daniel Litt ...someone would know a reference off the top of their head, since this question showed up very naturally in something else I've been thinking about recently.
Aug 10, 2015 at 19:21 comment added Daniel Litt @JasonStarr: I have indeed been looking at these papers. There are several minor issues (for example, I don't immediately see how to show that there is an unsplit family of rational curves in $X$, the first lemma in Andreatta-Wisniewski) which I think I now know how to deal with mostly. The main issue is the application of Lemma 1.2 of Campana-Peternell (arxiv.org/pdf/math/9607217.pdf), which I don't see how to improve to the case of a map which is not generically injective. But I am pretty new to this area, so I could just be missing something easy. In any case, I was hoping...
Aug 10, 2015 at 11:31 comment added Jason Starr Also, you might look at the articles of S'andor Kov'acs, Carolina Araujo, Stephane Druel, et al. They generalize Andreatta-Wisniewski in various ways. They may address your question.
Aug 10, 2015 at 11:30 comment added Jason Starr Can you point to a place in the article of Andreatta-Wisniewski where it is necessary for the sheaf homomorphism to be generically injective (as opposed to generically nonzero)? I realize that they state their result only for generically injective homomorphisms, but I do not immediately see a place where this is necessary.
Aug 10, 2015 at 4:49 history edited Daniel Litt CC BY-SA 3.0
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Aug 10, 2015 at 0:23 comment added Ben Webster @J.C.Ottem Thanks for the clarification. If Grassmannians don't work, it seems hard to imagine anything else would.
Aug 9, 2015 at 13:59 comment added J.C. Ottem @BenWebster The tensor product of two ample vector bundles is again ample, yet the only variety with ample tangent bundle is $P^n$. For the Grassmannian, the tangent bundle is however globally generated, for the reason you mentioned.
Aug 9, 2015 at 12:58 comment added Ben Webster I honestly don't understand the definitions well enough to be sure, but other Grassmannians seem like a good target; their tangent bundles are the tensor product of two bundles which I think are ample.
Aug 9, 2015 at 1:56 history asked Daniel Litt CC BY-SA 3.0