USNA Mathematics Department seminar

The talks for the academic year 1998-99 are held in Chauvenet 116 at 3:45 pm unless otherwise stated.

 

Speaker:

Caroline Melles


USNA

 

Title:

Coherent Ideal Sheaves and Blow-ups


 

Abstract: Complex analytic geometry deals with curves, surfaces, and higher-dimensional objects defined by analytic functions over the complex numbers (i.e. by holomorphic functions). Such objects are called analytic varieties and may be smooth or singular. This talk will focus on the case of a singular complex analytic variety X contained in a larger smooth variety M. A famous theorem of Hironaka says that the singularities of X may be resolved by a finite sequence of transformations called blow-ups, each of which replaces a smooth subvariety of the singular set of X by a larger smooth variety.

A blow-up can also be defined using a coherent ideal sheaf. A sheaf on an analytic variety is a structure which encodes local information over the entire variety. Coherent sheaves are locally finitely generated and are particularly useful. A coherent ideal sheaf on M determines a subvariety of M by encoding the local defining functions for that subvariety. This talk will describe desingularization using a single blow-up along a coherent ideal sheaf, which replaces a sequence of blow-ups along smooth subvarieties, and will discuss some applications in the construction of Chern forms and metrics for singular analytic varieties.

 

Time: Tuesday, April 27, 1999

 

Reception at 3:30 in the common room on the 3rd floor of Chauvenet Hall.