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Jun 17, 2015 at 15:12 vote accept Li Yutong
Jun 16, 2015 at 20:08 comment added pbelmans I just looked at page 86, and there he doesn't explicitly say that his varieties / schemes are projective. But later on in the context of Fourier--Mukai transforms everything is projective, so it turns out fine where he applies things. I guess he didn't want to be too elaborate on $f^\times$ and $f^!$ in this preliminary section...
Jun 16, 2015 at 19:57 comment added Li Yutong Okay, I see....
Jun 16, 2015 at 19:56 comment added pbelmans All varieties in the book of Huybrechts are taken to be (smooth) projective, and all morphisms between these are projective themselves. So he didn't have to put in the properness, it is there to start with.
Jun 16, 2015 at 17:57 comment added pro I humbly think that Huybrechts forgot a properness assumption, either on X and Y or f. To add to dracula's comment below: the right adjoint to $Rf_*$ exists pretty much always, purely for formal reasons. However, people often denote it by $f^\times$, as $f^!$ is reserved for the more sophisticated "twisted inverse image". The two $f^\times, f^!$ coincide when $f$ is proper.
Jun 16, 2015 at 17:42 answer added Count Dracula timeline score: 2
Jun 16, 2015 at 15:16 history edited Li Yutong CC BY-SA 3.0
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Jun 16, 2015 at 15:10 history asked Li Yutong CC BY-SA 3.0