Abstract

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In the study of geometric minimal models in dimension three, singularities naturally 

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appear. They are in practice quite mild, in particular they are always Q-factorial. I 

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will explain this delicate geometric property homologically, and give characterizations 

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of it on the derived level.  These characterizations come out of, and hence are related 

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to, the study of maximal modification algebras. This talk is based on joint work with Iyama.