On Higher Massey Products and Rational Formality for Moment—Angle Manifolds over Multiwedges

Abstract

We prove that certain conditions on multigraded Betti numbers of a simplicial complex K imply the existence of a higher Massey product in the cohomology of a moment-angle complex ZK, and this product contains a unique element (a strictly defined product). Using the simplicial multiwedge construction, we find a family ℱ of polyhedral products being smooth closed manifolds such that for any l, r ≥ 2 there exists an l-connected manifold M∈ ℱ with a nontrivial strictly defined r-fold Massey product in H*(M). As an application to homological algebra, we determine a wide class of triangulated spheres K such that a nontrivial higher Massey product of any order may exist in the Koszul homology of their Stanley–Reisner rings. As an application to rational homotopy theory, we establish a combinatorial criterion for a simple graph Γ to provide a (rationally) formal generalized moment-angle manifold ZPJ=(D¯2ji,S¯2ji−1)∂P*J = (j1,…,jm), over a graph-associahedron P = PΓ, and compute all the diffeomorphism types of formal moment-angle manifolds over graph-associahedra.