Six-dimensional exceptional quotient singularities
Six-dimensional exceptional quotient singularities
We classify six-dimensional exceptional quotient singularities and show that sevendimensional exceptional quotient singularities do not exist.Inter alia we prove that the irreducible six-dimensional projective representation of the sporadic simple Hall-Janko group gives rise to an exceptional quotient singularity.We assume that all varieties are projective, normal, and defined over C.