Freeness of Hyperplane Arrangements between Boolean Arrangements and Weyl Arrangements of Type Bl

Every subarrangement of Weyl arrangements of type B-l is represented by a signed graph. Edelman and Reiner characterized freeness of subarrangements between type A(l-1 )and type B-l in terms of graphs. Recently, Suyama and the authors characterized freeness for subarrangements containing Boolean arrangements satisfying a certain condition. This article is a sequel to the previous work. Namely, we give a complete characterization for freeness of arrangements between Boolean arrangements and Weyl arrangements of type B-l in terms of graphs.