The Monodromy Conjecture asserts that if c is a pole of the local topological zeta function of a hypersurface, then exp(2πic) is an eigenvalue of the monodromy on the cohomology of the Milnor fiber. A stronger version of the conjecture asserts that every such c is a root of the Bernstein-Sato polynomial of the hypersurface. In this note we prove the weak version of the conjecture for hyperplane arrangements. Furthermore, we reduce the strong version to the following conjecture: −n/d is always a root of the Bernstein-Sato polynomial of an indecomposable essential central hyperplane arrangement of d hyperplanes in Cn.
Budur, Nero; Mustaţă, Mircea; and Teitler, Zach. (2011). "The Monodromy Conjecture for Hyperplane Arrangements". Geometriae Dedicata, 153(1), 131-137. http://dx.doi.org/10.1007/s10711-010-9560-1