Let Q be a quiver with dimension vector α prehomogeneous under the action of product general linear groups GL(α) on representation variety Rep(Q,α). We study geometric properties zero sets semi-invariants this space. It is known that for large numbers N, nullcone in Rep(Q,N⋅α) becomes complete intersection. First, we show it also reduced. Then, using Bernstein–Sato polynomials, discuss some cri...