The dual complex of singularities

Seminar: 
Algebraic and Tropical Geometry
Event time: 
Thursday, April 25, 2013 - 12:30pm to 1:30pm
Location: 
431 DL
Speaker: 
Chenyang Xu
Speaker affiliation: 
University of Utah and Beijing International Center for Mathematical Research
Event description: 

The dual complex of a singularity is originally defined as the homotopy class of CW complexes which characterize how the exceptional divisors in a log resolutions intersect each other. Using MMP, for isolated singularities, we indeed find a canonical representative of the dual complex which is defined up to PL homeomorphism. The same method also answers the question that the dual complex of a klt singularity is always contractible. This is a joint work with de Fernex and Koll’ar.