Let $X$ be a smooth degree $d$ ($d>5$) surface in $\mathbb{P}^3$. We now blow up $X$ at a point and embedd it in $\mathbb{P}^3$. The question is does this resulting surface have on …

Consider the problem of classifying the finite groups of isometries of R^n. --For n=2 it is cyclic and dihedral groups. --For n=3 they are well known, probably from Kepler and are …

The ADE type Dynkin diagrams seem to come up in seemingly different areas of math. Two places they come up are: (1) Classification of simply laced complex simple lie algebras. (2 …

We all know that a simple singularity $W_G(x_1,x_2,x_3)=0$ of type G=A,D,E has the following nice deformation involving the Cartan subalgebra $\mathfrak{h}$ of the Lie algebra $\ma …

The ordinary McKay correspondence relates the subgroups of SU(2) to the affine ADE Dynkin diagrams. The correspondence is that the vertices correspond to irreducible representatio …

Recall that a certain type of object admits an ADE classification if there is a notion of equivalence relative to which equivalence classes of objects of the given type can be plac …

Let me start with a question for which I know the answer. Consider a symmetric integral $n\times n$ matrix $A=(a_{ij})$ such that $a_{ii}=2$, and for $i\ne j$ one has $a_{ij}=0$ or …

Possible Duplicate: ADE type Dynkin diagrams What is your favorite ADE-style classification? Here ADE style is to be understood in a very broad sense. A classification w …