A new linear quotient of C 4 admitting a symplectic resolution

Abstract

We show that the quotient C[superscript 4]/G admits a symplectic resolution for G = Q[subscript 8] x [subscript Z/2]D[subscript 8] < Sp[subscript 4](C). Here Q[subscript 8] is the quaternionic group of order eight and D[subscript 8] is the dihedral group of order eight, and G is the quotient of their direct product which identifies the nontrivial central elements −Id of each. It is equipped with the tensor product representation C[superscript 2] ⊠ C[superscript 2] ≅ C[superscript 4]. This group is also naturally a subgroup of the wreath product group Q[superscript 8][subscript 2] ⋊ S[subscript 2] < Sp[subscript 4](C). We compute the singular locus of the family of commutative spherical symplectic reflection algebras deforming C[superscript 4]/G. We also discuss preliminary investigations on the more general question of classifying linear quotients V/G admitting symplectic resolutions.