Resonance formula for Chen groups of arrangements
Let A\mathcal{A}A be a complex hyperplane arrangement with arrangement group G=G(A)G=G(\mathcal{A})G=G(A). Write the resonance variety as R1(A)=⋃iLiR_1(\mathcal{A})=\bigcup_i L_iR1(A)=⋃iLi, where the LiL_iLi ar…