(1) Departamento de Matemáticas, Facultad de Ciencias, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain;(2) Departamento de Matemáticas, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
Abstract:
We introduce the concept of s–formal minimal model as an extension of formality. We prove that any orientable compact manifold M, of dimension 2n or (2n−1), is formal if and only if M is (n−1)–formal. The formality and the hard Lefschetz property are studied for the Donaldson submanifolds of symplectic manifolds
constructed in 13]. This study permits us to show an example of a Donaldson symplectic submanifold of dimension eight which
is formal simply connected and does not satisfy the hard Lefschetz theorem.
An erratum to this article is available at .