On the volume of isolated singularities

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Yuchen Zhang , University of Utah
Fine Hall 322

Boucksom, de Fernex and Favre defined a non-log-canonical volume to study isolated singularities and developed several geometric results. Their definition is based on the intersection number of nef envelope of the log discrepancy b-divisor. In this talk, I will give an alternate definition of this volume by log canonical modification. I will study the lower bound of the volume in Gorenstein case using the new definition. Finally, I will give a threefold X with volume 0 but has no boundary \Delta such that the pair (X,\Delta) is log canonical.