2012/05/24 by Hoge, Torsten, Roehrle, Gerhard
#14N20 #20F55 #52B30 #52C35 #Commutative Algebra (math.AC) #FOS: Mathematics #Group Theory (math.GR)
paper · doi:10.48550/arxiv.1205.5430
Suppose that W is a finite, unitary, reflection group acting on the complex vector space V. Let A = A(W) be the associated hyperplane arrangement of W. Terao has shown that each such reflection arrangement A is free. Let L(A) be the intersection lattice of A. For a subspace X in L(A) we have the restricted arrangement AX in X by means of restricting hyperplanes from A to X. In 1992, Orlik and Terao conjectured that each such restriction is again free. In this note we settle the outstanding cases confirming the conjecture.