English

McKay correspondence over non algebraically closed fields

Algebraic Geometry 2015-04-02 v4 Representation Theory

Abstract

The classical McKay correspondence for finite subgroups GG of \SL(2,\C)\SL(2,\C) gives a bijection between isomorphism classes of nontrivial irreducible representations of GG and irreducible components of the exceptional divisor in the minimal resolution of the quotient singularity \A\C2/G\A^2_\C/G. Over non algebraically closed fields KK there may exist representations irreducible over KK which split over Kˉ\bar{K}. The same is true for irreducible components of the exceptional divisor. In this paper we show that these two phenomena are related and that there is a bijection between nontrivial irreducible representations and irreducible components of the exceptional divisor over non algebraically closed fields KK of characteristic 0 as well.

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Cite

@article{arxiv.math/0601550,
  title  = {McKay correspondence over non algebraically closed fields},
  author = {Mark Blume},
  journal= {arXiv preprint arXiv:math/0601550},
  year   = {2015}
}

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21 pages