Massey products in singularity links (Q1060252)

Let M be a link of isolated surface singularity. Then \(H^ 1(M)\) has a canonical weight filtration defined by Deligne: \(W_ 0H^ 1(M)\subset W_ 1H^ 1(M)\subset H^ 1(M).\) The main result of this paper is the following characterization of \(W_ 0H^ 1(M):\) Theorem. \(W_ 0H^ 1(M)=\{a\in H^ 1(M);\quad <a,a,b>=0\quad for\quad any\quad b\in H^ 1(M)\}.\) Here \(<a,a,b>\) is the Massey product of a, a and b. For the proof, the author uses the plumbing structure of M and a result of Neumann.