Characteristic polynomials of Linial arrangements for exceptional root systems

摘要

The (extended) Linial arrangement L-Phi(m) is a certain finite truncation of the affine Weyl arrangement of a root system with a parameter m. Postnikov and Stanley conjectured that all roots of the characteristic polynomial of L-Phi(m) have the same real part, and this has been proved for the root systems of classical types.