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Kustin-Miller unprojection with complexes

Stavros Papadakis
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Abstract

A main ingredient for Kustin-Miller unprojection, as developed in (S. Papadakis and M. Reid, Kustin-Miller unprojection without complexes, math.AG/0011094), is the module Hom_R(I, \om_R), where R is a local Gorenstein ring and I a codimension one ideal with R/I Gorenstein. We prove a method of calculating it in a relative setting using resolutions. We give three applications. In the first we generalise a result of (F. Catanese et al., Embeddings of curves and surfaces, Nagoya Math. J. 154 (1999), 185-220). The second and the third are about Tom and Jerry, two families of Gorenstein codimension four rings with 9x16 resolutions.

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Stavros Papadakis. 2001-11-19. Kustin-Miller unprojection with complexes. https://arxiv.org/abs/math/0111195

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