Codimension 4 Gorenstein

This website accompanies my paper
   Gorenstein in codimension 4 - the general structure theory, 30 pp.
Algebraic Geometry in East Asia (Taipei Nov 2011), Advanced Studies in
Pure Mathematics 65 (2015) pp. 201-227, preprint arXiv:1304.5248, 30 pp.

Slides for MSRI lecture Apr 2013.

Magma scripts:

Magma code for Section 2.3, Example 3.
baby Magma code for calculation of 3.2.
Nonsingularity calculations for ZZ/3 Godeaux surfaces and
related varieties.
Magma code for Fun2 and MSRI lecture

Related papers and preprints:

David A. Buchsbaum and David Eisenbud, What makes a complex exact?
J. Algebra. 25 (1973) 259-268

David A. Buchsbaum and David Eisenbud, Algebra structures for finite
free resolutions, and some structure theorems for ideals of codimension 3,
American J Math 99 (1977) 447-485

Miles Reid, Parallel unprojection equations for ZZ/3 Godeaux surfaces
Notes, 9 pp.

Miles Reid, Fun in codimension 4, notes, 24 pp.

Duncan Dicks, Surfaces with p_g=3, K^2=4 and extension-deformation
theory, 1988, Warwick PhD thesis, 125 + vi pp.

Miles Reid, Surfaces with p_g=3, K^2=4 according to E. Horikawa
and Duncan Dicks, Proceedings of Algebraic geometry mini-symposium
(Tokyo Univ., Dec 1989), 1--22

Miles Reid, Graded rings and birational geometry, in Proc. of algebraic
geometry symposium (Kinosaki, Oct 2000), K. Ohno (Ed.), 1--72

Fabrizio Catanese, Wenfei Liu, Roberto Pignatelli, The moduli
space of even surfaces of general type with K^2=8, p_g=4 and q=0,
 arXiv:1209.0034, 29 pp.

Gavin Brown, Michael Kerber and Miles Reid, Fano 3-folds in codimension 4,
Tom and Jerry, Part I, Compositio 148 (May 2012) 1171--1194,
preprint arXiv:1009.4313, 33 pp.
    See also notes in progress Tutorial on T and J

Stavros Papadakis and Miles Reid, Kustin--Miller unprojection without complexes,
J. Alg. Geom. 13 (2004) 563--577, preprint arXiv:0011094, 18 pp.

Links:

Gavin Brown's graded ring database
The Magma online calculator.
Miles Reid's front page