The derived category of a GIT quotient
Abstract
Given a quasiprojective algebraic variety with a reductive group action, we describe a relationship between its equivariant derived category and the derived category of its geometric invariant theory quotient. This generalizes classical descriptions of the category of coherent sheaves on projective space and categorifies several results in the theory of Hamiltonian group actions on projective manifolds. This perspective generalizes and provides new insight into examples of derived equivalences between birational varieties. We provide a criterion under which two different GIT quotients are derived equivalent, and apply it to prove that any two generic GIT quotients of an equivariantly CalabiYau projectiveoveraffine manifold by a torus are derived equivalent.
 Publication:

arXiv eprints
 Pub Date:
 March 2012
 arXiv:
 arXiv:1203.0276
 Bibcode:
 2012arXiv1203.0276H
 Keywords:

 Mathematics  Algebraic Geometry;
 Mathematics  KTheory and Homology;
 Mathematics  Representation Theory;
 14XX (primary) 19Exx;
 20Gxx (secondary)
 EPrint:
 38 pages, 1 figures