English

Derived categories of resolutions of cyclic quotient singularities

Algebraic Geometry 2017-09-13 v2

Abstract

For a cyclic group GG acting on a smooth variety XX with only one character occurring in the GG-equivariant decomposition of the normal bundle of the fixed point locus, we study the derived categories of the orbifold [X/G][X/G] and the blow-up resolution Y~X/G\widetilde Y \to X/G. Some results generalise known facts about X=AnX = A^n with diagonal GG-action, while other results are new also in this basic case. In particular, if the codimension of the fixed point locus equals G|G|, we study the induced tensor products under the equivalence Db(Y~)Db([X/G])D^b(\widetilde Y) \cong D^b([X/G]) and give a 'flop-flop=twist' type formula. We also introduce candidates for general constructions of categorical crepant resolutions inside the derived category of a given geometric resolution of singularities and test these candidates on cyclic quotient singularities.

Keywords

Cite

@article{arxiv.1701.01331,
  title  = {Derived categories of resolutions of cyclic quotient singularities},
  author = {Andreas Krug and David Ploog and Pawel Sosna},
  journal= {arXiv preprint arXiv:1701.01331},
  year   = {2017}
}

Comments

34 pages, many improvements from review, to appear in Quarterly J. Math