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Apr 17, 2023 at 10:16 comment added The Amplitwist The link to springerlink.com is broken. I'm also unable to find any snapshot saved on the Wayback Machine.
Jun 25, 2012 at 16:35 comment added EricM Thank you for your comments! You are correct that a priori my definition is special, however on a Del Pezzo surface it turns out to be equivalent (see [Helix Theory](cdsweb.cern.ch/record/737489/files/sis-2004-233.ps) - Section 4.4, page 30). I will update the definition so that I do not assume this. You are also correct about $Hom$ - I have made the adjustment.
Jun 25, 2012 at 16:31 history edited EricM CC BY-SA 3.0
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Jun 22, 2012 at 23:19 comment added Anton Fonarev Your definition of an exceptional pair is very special. A usual one asks only for $Ext^\bullet(F, E)=0$. A pair is called strong if $Ext^i(E, F)=0$ for all $i>0$. Also when one defines mutations, $Hom$ is taken in the derived sense.
Jun 22, 2012 at 18:37 history asked EricM CC BY-SA 3.0