Unimodularity of Poincaré polynomials of Lie algebras for semisimple singularities

We single out a large class of semisimple singularities with the property that all roots of the Poincaré polynomial of the Lie algebra of derivations of the corresponding suitably (not necessarily quasihomogeneously) graded moduli algebra lie on the unit circle; for a still larger class there might occur exactly four roots outside the unit circle. This is a corrected version of a theorem by Elashvili and Khimshiashvili.