Four-dimensional terminal Gorenstein quotient singularities.
Let \((X,0)\) be the germ of an isolated singularity and \(\pi:Y\longrightarrow X\) be a resolution with exceptional divisors \(E_1,\ldots,E_n\). The singularity is called terminal if \(mK_X\) is a Cartier divisor for some integer \(m>0\) and \(K_Y \equiv f^*K_X + \sum a_iE_i, a_i>0\) for all i. The finite subgroups \(G \subset \text{Gl}_4(\mathbb C)\) are classified such that \(\mathbb C^4/G\) has only terminal Gorenstein singularities.
scientific article; zbMATH DE number 2120990