KU-Jerusalem Lunch Seminar: Stavros Papadakis (University of Ioannina) An introduction to unprojection theory, part 1

Date: 
Thu, 16/03/202313:00-14:00
Location: 
Levy 6 hall and Zoom
Zoom Link: https://huji.zoom.us/j/84511564169?pwd=SkJmY285YnFIWkZqNmxuaVZsVVQ2UT09

Meeting ID: 845 1156 4169

Passcode:    171220

Title:  An introduction to unprojection theory, part 1 

Abstract:

Unprojection theory is a theory, due to Miles Reid, which constructs andanalyzes complicated commutative rings in terms of simpler ones. The main reference is [M. Reid, Graded rings and birational geometry, in Proc. of Algebraic Geometry Symposium (K. Ohno, ed.), Kinosaki, Oct. 2000, pp.~1--72]. Unprojection theory reinterprets and generalizes a construction due to Andrew Kustin and Matthew Miller from the 1980s. It has been used for the study of the explicit birational geometry of projective algebraic varieties and for constructing new Fano 3-folds, Calabi-Yau 3-folds and regular surfaces of general type. It also gives an intrinsic algebraic treatment, on the level of  Stanley-Reisner rings, of the stellar subdivision of a Gorenstein* simplicial complex. The aim of the talk is to present a gentle introduction to the theory.