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Varieties Which are almost D ‐Affine
Author(s) -
Holland Martin P.
Publication year - 1993
Publication title -
bulletin of the london mathematical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.396
H-Index - 48
eISSN - 1469-2120
pISSN - 0024-6093
DOI - 10.1112/blms/25.4.321
Subject(s) - mathematics , quotient , mod , functor , affine transformation , torsion (gastropod) , pure mathematics , equivalence (formal languages) , discrete mathematics , medicine , surgery
This paper produces several examples of varieties X for which the global sections functor Γ( X ,–): D X ‐ mod → D ( X )‐ mod is exact, and makes D ( X )‐ mod a quotient category of D X ‐ mod , but is not an equivalence. These varieties are quotients by finite group actions of D ‐affine varieties. The torsion of Γ( X ,–) is also described, in some cases. Here, D x ‐ mod denotes the category of quasi‐coherent D X ‐modules.